Oecumenius 

“Abraham is the image of someone who is justified by faith alone, since what he believed was credited to him as righteousness. But he is also approved because of his works, since he offered up his son Isaac on the altar. Of course he did not do this work by itself; in doing it, he remained firmly anchored in his faith, believing that through Isaac his seed would be multiplied until it was as numerous as the stars.” (Gerald Bray, ed., Ancient Christian Commentary on Scripture: New Testament, Vol. XI, James, 1-2 Peter, 1-3 John, Jude (Downers Grove: InterVarsity Press, 2000), p. 33.)