Genesis 31:48

He said, “You shall take these seven ewe lambs from my hand so that it may be a witness to me, that I dug this well.”

rather it shall be a witness between us and you and between our generations after us, that we are to perform the service of Yahweh before Him with our burnt offerings and with our sacrifices and with our peace offerings, so that your sons will not say to our sons in time to come, “You have no portion in Yahweh.”’

And the sons of Reuben and the sons of Gad called the altar Witness; “For,” they said, “it is a witness between us that Yahweh is God.”