As strange as it may seem, there have been instances in which God has been manifest here on the earth in more than one form at the same time.
In section 2.2, it was shown that God has been manifest upon the earth in the form of a pillar of a could by day, and in section 2.3, it was shown that He has also been manifest in the form of a pillar of fire by night:
EXODUS 13:21 And the LORD went before them by day in a pillar of a cloud, to lead them the way; and by night in a pillar of fire, to give them light; to go by day and night:
EXODUS 13:22 He took not away the pillar of the cloud by day, nor the pillar of fire by night, from before the people.
These two examples demonstrate God manifest in two different forms at two different times—by day and by night. However, when the Children of Israel passed through the Red Sea, God was manifest in both of these forms at the same time:
EXODUS 14:19 ¶ And the angel of God, which went before the camp of Israel, removed and went behind them; and the pillar of the cloud went from before their face, and stood behind them:
EXODUS 14:20 And it came between the camp of the Egyptians and the camp of Israel; and it was a cloud and darkness to them, but it gave light by night to these: so that the one came not near the other all the night.
In Exodus 14:19 above, the phrase "angel of God" indicates the visible manifestation of God. Such usage of the word "angel" was explained briefly in section 4.5.1. This particular "angel of God" (or, manifestation of God) happened to be the pillar of a cloud from Exodus 13:21 (above), which was described in section 2.2.
In Exodus 14:20, we have seen that during that particular night, the LORD was manifest as both "a cloud and darkness" to the Egyptians, and as a "light by night" for Israel. At night, a pillar of a cloud provides no illumination, but a pillar of fire does. Furthermore, we know that God was manifest in both of these forms at the same time, because the narrative later says:
EXODUS 14:24 And it came to pass, that in the morning watch the LORD looked unto the host of the Egyptians through the pillar of fire and of the cloud, and troubled the host of the Egyptians,
Only one pillar is mentioned here: the pillar "of fire and of the cloud." Here, God was manifest in both of these forms at the same time. As before, this is not God in His true form, but a manifestation of God here upon the earth (or in this case, a multiple–manifestation of God).
We have already seen in section 2.4 that God was manifest before all the children of Israel in the form of thunders, lightnings, a thick cloud, and an exceedingly loud trumpet:
EXODUS 19:9 And the LORD said unto Moses, Lo, I come unto thee in a thick cloud, that the people may hear when I speak with thee, and believe thee for ever. And Moses told the words of the people unto the LORD.
EXODUS 19:10 ¶ And the LORD said unto Moses, Go unto the people, and sanctify them to day and to morrow, and let them wash their clothes,
EXODUS 19:11 And be ready against the third day: for the third day the LORD will come down in the sight of all the people upon mount Sinai.
EXODUS 19:16 And it came to pass on the third day in the morning, that there were thunders and lightnings, and a thick cloud upon the mount, and the voice of the trumpet exceeding loud; so that all the people that was in the camp trembled.
EXODUS 19:17 And Moses brought forth the people out of the camp to meet with God; and they stood at the nether part of the mount.
EXODUS 19:18 And mount Sinai was altogether on a smoke, because the LORD descended upon it in fire: and the smoke thereof ascended as the smoke of a furnace, and the whole mount quaked greatly.
EXODUS 19:19 And when the voice of the trumpet sounded long, and waxed louder and louder, Moses spake, and God answered him by a voice.
EXODUS 19:20 And the LORD came down upon mount Sinai, on the top of the mount: and the LORD called Moses up to the top of the mount; and Moses went up.
It was at this time, while God was manifest in this form(s), that He gave the Ten Commandments at Exodus 20:1-17. After the giving of the Ten Commandments, the narrative continues:
EXODUS 20:18 ¶ And all the people saw the thunderings, and the lightnings, and the noise of the trumpet, and the mountain smoking: and when the people saw it, they removed, and stood afar off.
EXODUS 20:19 And they said unto Moses, Speak thou with us, and we will hear: but let not God speak with us, lest we die.
EXODUS 20:20 And Moses said unto the people, Fear not: for God is come to prove you, and that his fear may be before your faces, that ye sin not.
EXODUS 20:21 And the people stood afar off, and Moses drew near unto the thick darkness where God was.
EXODUS 20:22 ¶ And the LORD said unto Moses, Thus thou shalt say unto the children of Israel, Ye have seen that I have talked with you from heaven.
Beginning at this time, according to the wish of the (frightened) children of Israel at Exodus 20:19, God no longer spoke to the congregation of Israel directly. From that time on, God spoke to them through Moses, who relayed His words to Israel.
At Exodus 20:21 above, Moses drew near to God, and for the next few days, received commandments, and instructions concerning judgement. (These commandments and judgements are written in the 21st, 22nd, and 23rd chapters of Exodus.) This time of instruction began at Exodus 20:21, and continued through Exodus 24:3. During this time, when viewed from the camp of the children of Israel, God was continually manifest as a cloud and a devouring fire at the top of Mount Sinai:
EXODUS 24:16 And the glory of the LORD abode upon mount Sinai, and the cloud covered it six days: and the seventh day he called unto Moses out of the midst of the cloud.
EXODUS 24:17 And the sight of the glory of the LORD was like devouring fire on the top of the mount in the eyes of the children of Israel.
According to Exodus 24:16, God was continually manifest in this form for seven days:
EXODUS 24:16 And the glory of the LORD abode upon mount Sinai, and the cloud covered it six days: and the seventh day he called unto Moses out of the midst of the cloud.
This seven day period began when God gave the Ten Commandments in Exodus 20, and ended at Exodus 24:18. It was at some point during this seven day period that Moses, Aaron, Nadab, Abihu, and seventy of the elders of Israel "saw the God of Israel," manifest in the form that was described in section 2.5:
EXODUS 24:1 And he [i.e., God,] said unto Moses, Come up unto the LORD, thou, and Aaron, Nadab, and Abihu, and seventy of the elders of Israel; and worship ye afar off.
EXODUS 24:9 ¶ Then went up Moses, and Aaron, Nadab, and Abihu, and seventy of the elders of Israel:
EXODUS 24:10 And they saw the God of Israel: and there was under his feet as it were a paved work of a sapphire stone, and as it were the body of heaven in his clearness.
EXODUS 24:11 And upon the nobles of the children of Israel he laid not his hand: also they saw God, and did eat and drink.
While God was manifest in this form to Nadab, Abihu, and the seventy elders of Israel, God was still manifest to the rest of the children of Israel as the cloud and devouring fire at the top of Mount Sinai (Exodus 24:16-17). We know this because in the next verse after the elders ate and drank before God, God called Moses up Mount Sinai to receive the two stone tablets of the Ten Commandments:
EXODUS 24:12 ¶ And the LORD said unto Moses, Come up to me into the mount, and be there: and I will give thee tables of stone, and a law, and commandments which I have written; that thou mayest teach them.
When Moses did go up a few verses later still, he went "into the midst of the cloud." (In other words, God was still manifest as the cloud after they ate and drank with God):
EXODUS 24:15 And Moses went up into the mount, and a cloud covered the mount.
EXODUS 24:16 And the glory of the LORD abode upon mount Sinai, and the cloud covered it six days: and the seventh day he called unto Moses out of the midst of the cloud.
EXODUS 24:17 And the sight of the glory of the LORD was like devouring fire on the top of the mount in the eyes of the children of Israel.
EXODUS 24:18 And Moses went into the midst of the cloud, and gat him up into the mount: and Moses was in the mount forty days and forty nights.
Beginning at Exodus 19:16-20, and continuing for seven days, to Exodus 24:18, God was manifest as a cloud and a devouring fire at the top of Mount Sinai. At some point during this timeframe, at Exodus 24:9-11, Moses, along with certain elders of Israel saw God manifest in that other form in which "hands" and "feet" were mentioned (see section 2.5). While Moses and the elders of Israel ate and drank before God (Exodus 24:11), the rest of Israel saw God as a cloud and a devouring fire (Exodus 19:18, Exodus 24:17). God was manifest in both of these forms at the same time. Later, after eating and drinking before God, Moses "went into the midst of the cloud" (Exodus 24:15-18), to receive the two stone tables of the Ten Commandments.
We have seen in section 3.2 that the Spirit of the LORD was upon Moses, and that the LORD took some of His spirit, and gave it to seventy of the elders of Israel:
NUMBERS 11:16 ¶ And the LORD said unto Moses, Gather unto me seventy men of the elders of Israel, whom thou knowest to be the elders of the people, and officers over them; and bring them unto the tabernacle of the congregation, that they may stand there with thee.
NUMBERS 11:17 And I will come down and talk with thee there: and I will take of the spirit which is upon thee, and will put it upon them; and they shall bear the burden of the people with thee, that thou bear it not thyself alone.
NUMBERS 11:24 ¶ And Moses went out, and told the people the words of the LORD, and gathered the seventy men of the elders of the people, and set them round about the tabernacle.
NUMBERS 11:25 And the LORD came down in a cloud, and spake unto him, and took of the spirit that was upon him, and gave it unto the seventy elders: and it came to pass, that, when the spirit rested upon them, they prophesied, and did not cease.
NUMBERS 11:26 But there remained two of the men in the camp, the name of the one was Eldad, and the name of the other Medad: and the spirit rested upon them; and they were of them that were written, but went not out unto the tabernacle: and they prophesied in the camp.
NUMBERS 11:27 And there ran a young man, and told Moses, and said, Eldad and Medad do prophesy in the camp.
NUMBERS 11:28 And Joshua the son of Nun, the servant of Moses, one of his young men, answered and said, My lord Moses, forbid them.
NUMBERS 11:29 And Moses said unto him, Enviest thou for my sake? would God that all the LORD'S people were prophets, and that the LORD would put his spirit upon them!
In Numbers 11:25, we see that God was manifest in the form of a cloud when He did this. Here, simultaneously, God was manifest both as a cloud and as the Holy Spirit at the same time.