{If thou art the Son of God} (ei huios ei tou theou). More
exactly, "If thou art Son of God," for there is no article with
"Son." The devil is alluding to the words of the Father to Jesus
at the baptism: "This is my Son the Beloved." He challenges this
address by a condition of the first class which assumes the
condition to be true and deftly calls on Jesus to exercise his
power as Son of God to appease his hunger and thus prove to
himself and all that he really is what the Father called him.
{Become bread} (artoi gen(936e)tai). Literally, "that these stones
(round smooth stones which possibly the devil pointed to or even
picked up and held) become loaves" (each stone a loaf). It was
all so simple, obvious, easy. It would satisfy the hunger of
Christ and was quite within his power. {It is written}
(gegraptai). Perfect passive indicative, stands written and is
still in force. Each time Jesus quotes Deuteronomy to repel the
subtle temptation of the devil. Here it is  De 8:3  from the
Septuagint. Bread is a mere detail (Bruce) in man's dependence
upon God.