Genesis 26:26-33 - Covenant With Abimelech
26 And Abimelech went to him from Gerar, and Ahuzzath his friend, and Phicol, leader of his army. 27 And Isaak will say to them, Wherefore came ye to me, and ye hated me, and will send me away from you?
28 And they will say, Seeing we saw that Jehovah was with thee: and we will say, There shall be an oath between us, between us and between thee, and we will make a covenant with thee. 29 Wilt thou do evil to us as that we touched thee not, as that we did to thee only good, and we sent thee away in peace, thou now art praised of Jehovah.
30 And he will make to them a drinking, and they will eat and drink. 31 And they will rise early in the morning, and they will swear, a man to his brother, and Isaak will send them away and they will go from him in peace.
32 And it shall be in that day, and Isaak's servants will come and announce to him concerning the well which they digged, and they will say to him, We found water. 33 And he will call it oath: for this the name of the city the well of the oath till this day.