Chessed and boundaries

Amon and Moav could not join Klal Yisrael for ten generations, and the Torah gives two reasons. One is that they hired Bilam to curse us. The other is that they did not meet us with bread and water. Those two do not seem to weigh the same. The Or HaChaim asks exactly that, and the Ramban looks back to Lot and what Avraham had done for him. A second answer looks at the one midah Lot was known for, and what the Torah expected of his descendants because of it.