The God invoked with the proper noun Yahweh is the same personal Being as that which the patriarchs invoked as ‘God the Father’. But the name in itself was only attributed to the God of Israel during the passing of the Hebrew nation through the human and religious experience of the exodus, led by Moses. It is with the memory of the exodus that the name of God of the Yahwist faith is inextricably associated. It was only centuries after this founding historical event that the faith of the people of the Bible gave an explanation to the holy tetragram, placing it in the context of the theophany that set off the exodus and making a hermeneutic of it. It did so by means of the assonance closest to it, with a verbal form hayah. Thus the name of God was understood in terms of ‘Being, Existing’, as ‘the truly Existing’ for the people, liberating it from slavery to be reconnected to Him by means of an alliance of friendship.