Deuteronomy 29:13-15

that he may establish thee this day unto himself for a people, and that he may be unto thee a God, as he spake unto thee, and as he sware unto thy fathers, to Abraham, to Isaac, and to Jacob. Neither with you only do I make this covenant and this oath, but with him that standeth here with us this day before Jehovah our God, and also with him that is not here with us this day