The thing about israel assimilating foreigners is that it was * a bad thing* as the "mixed multitude" immediately started complaining against God in the desert and the false converts led the Israelites astray into idolatry. Further on, after the Judeans returned from captivity in Babylon, some of them took wives from the women of the land, which was explicitly forbidden by the Law, and the priests literally had to start ordering them to divorce their foreign wives (not that the marriages were legitimate to begin with) lets they be led into idolatry again. So multiculturalism is literally anti-biblical, and the only way for a foreigner of a compatible culture to become a member of a culture biblically is after like ten generations, and the bible outright stated that certain races were forbidden from every being considered Hebrew, and methings these races are the ones we now call "Jews"