Genesis 31:44

In the same day the LORD made a covenant with Abram, saying, Unto thy seed have I given this land, from the river of Egypt unto the great river, the river Euphrates:

And it came to pass at that time, that Abimelech and Phichol the chief captain of his host spake unto Abraham, saying, God is with thee in all that thou doest: Now therefore swear unto me here by God that thou wilt not deal falsely with me, nor with my son, nor with my son's son: but according to the kindness that I have done unto thee, thou shalt do unto me, and to the land wherein thou hast sojourned. And Abraham said, I will swear. And Abraham reproved Abimelech because of a well of water, which Abimelech's servants had violently taken away. And Abimelech said, I wot not who hath done this thing; neither didst thou tell me, neither yet heard I of it, but to day. And Abraham took sheep and oxen, and gave them unto Abimelech; and both of them made a covenant. And Abraham set seven ewe lambs of the flock by themselves. And Abimelech said unto Abraham, What mean these seven ewe lambs which thou hast set by themselves? And he said, For these seven ewe lambs shalt thou take of my hand, that they may be a witness unto me, that I have digged this well. Wherefore he called that place Beersheba; because there they sware both of them. Thus they made a covenant at Beersheba: then Abimelech rose up, and Phichol the chief captain of his host, and they returned into the land of the Philistines.

And they said, We saw certainly that the LORD was with thee: and we said, Let there be now an oath betwixt us, even betwixt us and thee, and let us make a covenant with thee; That thou wilt do us no hurt, as we have not touched thee, and as we have done unto thee nothing but good, and have sent thee away in peace: thou art now the blessed of the LORD. And he made them a feast, and they did eat and drink. And they rose up betimes in the morning, and sware one to another: and Isaac sent them away, and they departed from him in peace.

And thou shalt not only while yet I live show me the kindness of the LORD, that I die not: But also thou shalt not cut off thy kindness from my house for ever: no, not when the LORD hath cut off the enemies of David every one from the face of the earth. So Jonathan made a covenant with the house of David, saying, Let the LORD even require it at the hand of David's enemies. And Jonathan caused David to swear again, because he loved him: for he loved him as he loved his own soul.