How did Moses speak to 3 to 4.5 million people?

Answer 1

Moses received Divine assistance in projecting his voice if and when he spoke to the Israelites all at once. Otherwise, he had the officers of tens (etc.) who were appointed for this very purpose (Exodus ch.18) and who conveyed his words among the Israelites. This system was followed in the Torah-academies in Babylonia as well.If you're asking about the Revelation at Sinai, that was God speaking, not Moses (Exodus ch.19-20).

See also:

Was Moses a real person?

Answer 2

The Bible says that 600,000 fighting men followed Moses out of Egypt. Even conservative estimates say that this would have been equivalent to at least 2.5 million people, including priests, the elderly, women and children. A figure as high as 3 to 4.5 million people is certainly possible.

One of the apparent puzzles of the story is that Moses is said to have spoken to all these people at once. In one example, Exodus 16:6 clearly portrays Moses and Aaron speaking directly to all the Israelites: "And Moses and Aaron said unto all the children of Israel ...". This can best be resolved by reference to the view of most scholars that the Exodus never really happen as described in the Bible. We do not have to find natural explanations for legendary accounts such as this.

Answer 3

Some think scripture does not say that all heard Moses' natural voice, only that he directed his words to all. The leaders would have ensured all who needed to know received the message.