Chapter 23
2 "No one born of a forbidden union may enter the assembly of the LORD. Even to the tenth generation, none of his descendants may enter the assembly of the LORD. [Deu 23:2 ESV]
MSB talks about how Egyptians and Edomites could worship in the third generation. Maybe this is about first cousins, or sons who married their stepmothers. That sort of forbidden marriage. This seems a very harsh penalty for the children so born, as it was not their choice, but they bear the brunt, and carry this through 10 generations. About 250 years!
The MSB note is actually quite long on this section. It states unequivocally that forbidden unions is about producing illegitimate children. The children of such a union could never, ever go into the Tabernacle, or later, into the Temple. This is an indication of how much importance God places on sanctioned marriage - between a man and a woman - more than it is a punishment of the innocent children that can result from immorality. The consequences to the progeny of such a union were so dire as to be an effective deterrent to immorality. And remember the woman at the well. Jesus offered her salvation despite her past and current indiscretions.
In the next verse, the same stipulation was put on Ammonites and Moabites because they refused to help Israel when they first came out of Egypt. For these two, it isn't just ten generations, it says forever. MSB also notes that the Ammonites and Moabites were in close geographic proximity to the tribes that stayed on the East side of Jordan, and this would have erected a "wall" against their intermingling.
These verses:
3 "No Ammonite or Moabite may enter the assembly of the LORD. Even to the tenth generation, none of them may enter the assembly of the LORD forever, ... 6 You shall not seek their peace or their prosperity all your days forever. 7 "You shall not abhor an Edomite, for he is your brother. You shall not abhor an Egyptian, because you were a sojourner in his land. 8 Children born to them in the third generation may enter the assembly of the LORD. [Deu 23:3, 6-8 ESV]
I would think that prophecies about Ammon and Moab would take this injunction into account, and that they are both destined to a bad end. But...they were descended from Lot...so maybe that affords them some eventual consideration.
I would expect that Edom and Egypt ultimately do ok.
15 "You shall not give up to his master a slave who has escaped from his master to you. 16 He shall dwell with you, in your midst, in the place that he shall choose within one of your towns, wherever it suits him. You shall not wrong him. [Deu 23:15-16 ESV]
Isn't this interesting in the context of the slave who escapes his master in the NT, prompting a whole letter from Paul urging the old master to take it easy on the escaped slave when he comes "home"? This seems unusual. MSB note says it likely referred to escaped Canaanite slaves who came to Israel seeking to know their God and assimilate into their culture.
Here is another verse that indirectly shows up in the NT:
25 If you go into your neighbor's standing grain, you may pluck the ears with your hand, but you shall not put a sickle to your neighbor's standing grain. [Deu 23:25 ESV]
Remember when Jesus and his disciples went through the field on the Sabbath and picked some corn to eat. The Pharisees didn't call it stealing from the one the field belonged to, but they did say it shouldn't have been done on the Sabbath. This verse adds some depth and context to that whole incident.