John Calvin Commentary John 5:26

"For as the Father hath life in himself, even so gave he to the Son also to have life in himself:" — John 5:26 (ASV)

For as the Father has life in himself. He shows from where his voice derives such efficacy; namely, that he is the fountain of life, and by his voice pours it out on humanity; for life would not flow to us from his mouth, if he did not have in himself the cause and source of it.

God is said to have life in himself, not only because he alone lives by his own inherent power, but because, containing in himself the fullness of life, he communicates life to all things. And this, indeed, belongs uniquely to God, as it is said, With you is the fountain of life (Psalms 36:9), but because the majesty of God, being far removed from us, would resemble an unknown and hidden source, for this reason it has been openly manifested in Christ.

We have thus an open fountain placed before us, from which we may draw. The meaning of the words is this: “God did not choose to have life hidden, and, as it were, buried within himself, and therefore he poured it into his Son, that it might flow to us.” Hence we conclude, that this title is strictly applied to Christ, so far as he was manifested in the flesh.