Jamieson, Fausset & Brown

Before Abraham was, I am--The words rendered "was" and "am" are quite different. The one clause means, "Abraham was brought into being"; the other, "I exist." The statement therefore is not that Christ came into existence before Abraham did (as Arians affirm is the meaning), but that He never came into being at all, but existed before Abraham had a being; in other words, existed before creation, or eternally (as Joh 1:1). In that sense the Jews plainly understood Him, since "then took they up stones to cast at Him," just as they had before done when they saw that He made Himself equal with God (Joh 5:18). hid himself--(See on Luk 4:30). Next: John Chapter 9