For whom were Israelites to leave the edges of their fields and their fallen grapes?

Answer: The poor and the foreigner

Leviticus 19:9-10 told farmers not to reap the very edges or gather gleanings and fallen grapes, but leave them for the poor and foreigner.

“When you reap the harvest of your land, you are not to reap to the very edges of your field or gather the gleanings of your harvest. You must not strip your vineyard bare or gather its fallen grapes. Leave them for the poor and the foreigner. I am the LORD your God.”— Leviticus 19:9-10 (BSB)