https://theologyinfive.com/the-importance-of-the-number-70-in-the-bible/
Jacobs Family: In Genesis 46:27, it is mentioned that 70 members of Jacobs family went down to Egypt. This number signifies the totality of the Israelite nation at that time, originating from the 12 sons of Jacob.
Elders of Israel: In Exodus 24:1 and Numbers 11:16-17, God instructed Moses to gather 70 elders of Israel to help him govern the people. These elders represented the whole nation and were chosen to assist Moses in leading the Israelites.
Babylonian Exile: According to the prophet Jeremiah (Jeremiah 29:10), the Israelites were to be exiled in Babylon for 70 years as a divine punishment for their disobedience. This period of exile symbolized a time of judgment and purification for the nation.
Daniels Prophecy: In the book of Daniel (Daniel 9:24-27), the prophecy of Seventy Weeks is given, which outlines a timeline of significant events related to the Jewish people and the coming of the Messiah. The number 70 here is used in a symbolic manner to represent a complete and predetermined period.