Who did say Yahweh to not distress and why?

Answer From The Annual Reading Schedule - Week 42 Notes For Deuteronomy: Mo'av (Moab) and Ammon – because He does not give their land to Yisra'el – but Ar is given to the descendants of Lot and the land of the children of Ammon as well (Deuteronomy 2:9, 19).