I’m currently participating in The Bible in a Year Podcast (unsponsored but you should totally do it, very well made). We are currently in Numbers and Dueteronomy, and in the book of Numbers, there seems to be pages and pages of lists of families and their names, specifically in Numbers 26. What is the significance of having these here? What importance did they have to their Jewish ancestors?
The list of names in Numbers chapter 26 has a direct relationship with the list of names in chapter 1. The whole book of Numbers covers 39 years, which equals the time of their desert wanderings. At the start, God commanded Moses to take a census of the people on the 1st day of the 2nd month in the 2nd year of their exodus (ch. 1). At chapter 26 of the book, after God had sent a plague on the disobedient, sexually immoral Israelites (still in the wilderness), God commanded Moses to take a second census. Note the similarities, and the significance of the time gap.
The first census in ch. 1 was taken while the nation of Israel was still in the Desert of Sinai, on the second year after they had come out of Egypt. God told Moses:
"Take a census of the whole Israelite community by their clans and families, listing every man by name, one by one. You and Aaron are to number by their divisions all the men in Israel 20 years old or more who are able to serve in the army" (1:1-2)
The census revealed 603,550 of those men from eleven tribes (vs.47-49) for none of the tribe of Levi were to be counted, as that was the priestly tribe. Now look at chapter 26.
"After the plague the Lord said to Moses and Eleazar son of Aaron the priest, 'Take a census of the whole Israelite community by families - all those 20 years old or more who are able to serve in the army of Israel'. So on the plains of Moab by the Jordan across from Jericho [the census was taken]" (26:1-3).
The second census revealed 601,730 men from the 11 tribes - and the significance is two-fold. Not one of the Israelites who had wandered in the wilderness for 40 years was still alive (apart from those tiny few God said would be spared, to enter into the Promised Land). They had all died in the wilderness according to God's judgment on their lack of faith at the first attempt to take the Land. The second census showed that it was their children - the next generation - who would take the Land via those men counted to be in the army, starting with Jericho. That is why the last chapters deal with the boundaries of the Land. Chapter 26:52-56 shows the allocation of it to the tribes.
Therefore, the significance of those two lists of names for the Israelites was:
(1) To prove God had carried out his promise, that none of the faithless Israelites who he took out of Egypt would inherit the Promised Land -
"The Lord's anger was aroused that day and he swore this oath: 'Because they have not followed me wholeheartedly, not one of the men twenty years old or more who came up out of Egypt will see the land I promised on oath to Abraham, Isaac and Jacob - not one except Caleb the son of Jephunneh the Kenizzite and Joshua son of Nun, for they followed the Lord wholeheartedly.' The Lord's anger burned against Israel and he made them wander in the desert for forty years, until the whole generation of those who had done evil in his sight was gone." (Numbers 32:10-13)
(2) The survivors of that disobedient generation would learn a mighty lesson from this, plus know that God's oath to Abraham was still to be carried out, with them being the tribes allocated particular portions of the Promised Land. That awesome knowledge would fortify them for crossing Jordan to take Jericho, and for all the other battles ahead, and mean that the apportioning of the land would be done according to God's stated will. This lesson they would then pass on to their generation, and so the account of the Exodus would stay in the nation forever, the good and the bad bits together.