Genesis 22:10

And Abraham stretched forth his hand
All things being ready for execution, the altar built, the wood laid on it, the sacrifice bound and laid on that, nothing remained but to cut the throat of the sacrifice; and in order to that, the instrument for it laying by him, he put forth his hand, one would think in a trembling manner, for it is enough to make one tremble to think of it:

and took the knife to slay his son;
with a full intention to do it, which was carrying his obedience to the divine will to the last extremity, and shows he was sincere in it, and really designed to complete it; and this was taken by the Lord as if it was actually done. He had his knife in his hand, and was near the throat of his son, and just ready to give the fatal thrust; in another moment, as it were, it would have been all over; but in the nick of time God appeared and prevented it, as follows: