Christ’s fullness to save.
Because of his divinity and the Spirit being given him without measure for the work of our salvation: “He is able also to save them to the uttermost that come unto God by him,” Heb. 7:25; having all fullness unto this end communicated unto him: “for it pleased the Father that in him should all fullness dwell,” Col. 1:19; and he received not “the Spirit by measure,” John 3:34. And from this fullness he makes out a suitable supply unto all that are his; “grace for grace,” John 1:16. Had it been given to him by measure, we had exhausted it.
He surely is an unfathomable and eternal source of the (spiritual) water of life that never runs out (John 8)—JK
And as with real water, his water continues to satisfy our thirst for God.