What did God promise Abraham about Egypt and Israel's departure in Genesis 15:14?

Scripture teaches that God promised Abraham He would judge Egypt, the nation that would enslave his descendants. After that judgment, the children of Israel would depart from Egypt and come out with great substance, fulfilling God's word to Abraham in Genesis 15:14.

Les teaches that in Genesis 15:14 God told Abraham He would judge the nation Egypt that would enslave his descendants, and afterward the children of Israel would come out with great substance. The surrounding context shows Abraham was also told he would die after a good old age, and in the fourth generation they would return to Canaan. Les explains this was all prophesied: Israel would be in a land not theirs, Egypt, under slavery and bondage, but God would bring them back to the promised land. The delay also involved giving the Amorites four hundred years to change their ways or become so bad that God could justly have Israel annihilate them.

Genesis 15:14

And also that nation, whom they shall serve, will I judge: and afterward shall they come out with great substance.

What did God promise Abraham about the nation Israel would serve and their exit from it?

God promised Abraham that the nation they would serve—Egypt—would be judged, and afterward the children of Israel would come out with great substance. They would be in bondage in a land not theirs, but God would bring them back to the promised land after 430 years, in the fourth generation.