And when he had fasted … he was afterwards an hungred. He was so absorbed in prayer that it was only after his six weeks meditation that he felt the need of food. But though his humanity had been elevated and his spiritual sense quickened by this at the time almost unconscious fast, it left him physically prostrate and completely exposed to attack.
"In certain morbid conditions, which involve a more or less entire abstinence from food, a period of six weeks generally brings about a crisis, after which the demand for nourishment is renewed with extreme urgency.
The exhausted body becomes a prey to a deathly sinking. Such, doubtless, was the condition of Jesus; he felt himself dying. It was the moment the tempter had waited for to make his decisive assault" (Godet).
Luke probably (though not in the Revised Version) represents the temptation as continuous during the whole period. Of this Matthew says nothing, but only describes the final scenes, when the might of the tempter was felt to the uttermost, and his defeat was most crucial.
Forty. Trench's remark is well worth study: "On a close examination we note it to be everywhere there [i.e. in Holy Scripture] the number or signature of penalty, of affliction, of the confession, or the punishment, of sin.
Nights. The mention of nights as well as days brings out more vividly the continuance and the completeness of the abstinence (cf Genesis 7:4, Genesis 7:12 [17, LXX.]; Exodus 24:18; Deuteronomy 9:1-29, especially Deuteronomy 9:18; 1 Kings 19:8).