Albert Barnes on Matthew 4:2

Had fasted. Abstained from food.

Forty days and forty nights. It has been questioned by some whether Christ abstained wholly from food, or only from bread and the food to which he was accustomed. Luke says, (Lk 4:2,) that he ate nothing. This settles the question. Mark says, Mk 1:13, that angels came and ministered unto him. At first view, this would seem to imply that he did eat during that time. But Mark does not mention the time when the angels performed the office of kindness; and we are at liberty to suppose that he meant to say that it was done at the close of the forty days; and the rather as Matthew, after giving an account of the temptation, says the same thing, Mk 4:2. There are other instances of persons fasting forty days, recorded in the Scriptures. Thus Moses fasted forty days, Ex 34:28. Elijah also fasted the same length of time, 1Kgs 19:8. In these cases, they were no doubt miraculously supported.