There are three places regarding which the nations cannot accuse Israel and say, "You have stolen them": the cave of Machpeilah, as it is written: "And Abraham weighed to Ephron the silver" (Genesis 23:16); the Temple Mount, as it is written, "So David gave to Ornan for the place six hundred shekels of gold" (I Chronicles 21:25); and Joseph's tomb -- "And [Jacob] bought the parcel of land for a hundred pieces of silver" (Genesis 33:19)
Midrash Rabbah, Bereishit 33:19
