He did not say, That they may believe that I am inferior to Thee, in that I cannot do this without prayer, but, that Thou hast sent Me. He saith not, hast sent Me weak, acknowledging subjection, doing nothing of Myself, but hast sent Me in such sense, as that man may see that I am from God, not contrary to God; and that I do this miracle in accordance with His will.
Reproduced in full. Translation: Oxford 1841 (Newman), public domain (Public domain).
Also cites: Hom. lxiv. 2