Matthew Poole and continuators on Genesis 22:12

12 And he said, lay not thine hand upon the lad, neither do thou any thing unto him; for now I know that thou fearest God, seeing thou hast not with-held thy son, thine onely son from me .

God knew the sincerity and resolvedness of Abrahams faith and obedience before and without this evidence, and from eternity foresaw this fact and all its circumstances; and therefore you must not think that God had now made any new discovery. But this is spoken here, as in many other places, of God after the manner of men, who is then said to know a thing, when it is notorious and evident to a mans self and others by some remarkable effect. Thus David prayeth that God would search and know his Heart, and his thoughts, Psal. 139. 23. Though he had before professed that God understood his thought afar off, ver. 2. This therefore is the sense, Now I know, i. e, Now I have what I designed and desired, now I have made thee and others to know: As the Spirit of God and of Christ is said to cry Abba, Father, Gal. 4. 6. when it makes us to cry so, Rom. 8. 15.

From my service and Sacrifice: Or for me. i. e. for my sake. i. e. thou hast preferred mine Authority and Honour before the Life of thy dear Son. By which word it appears that God himself speaks these words.