Genesis 15:10

This was probably an ancient custom when people make a firm agreement with each other. Perhaps it was like this. Two people kill animals as an *offering to God and they cut the animals into two parts. They separate the parts and they walk between the parts. That shows that they must keep the agreement. Otherwise, someone will cut the people into two parts. God used this custom to show that his agreement with Abram was firm. So Abram separated the two parts of each animal. Then fire appeared and it moved between the two parts. (See verse 17.) The fire was a sign of God.

v12 When the sun set, Abram slept. He felt fear and there was great darkness. v13 Then the *Lord said to Abram, ‘Be certain about what I tell you. Your *descendants will live in a country that does not belong to them. They will be slaves there. They will have to work hard for 400 years. v14 But I will punish the nation that they serve. Afterwards your *descendants shall come out of that country. They shall take with them many possessions. v15 You yourself shall die in peace and then you shall be with your fathers. When people shall bury you, you will be very old. v16 And your *descendants shall come back to this country. The sons of the sons of the sons of your sons shall come back. But before they come back the Amorites must do still more evil things.’