Ramban on Genesis 45:6/רמב"ן על בראשית מ״ה:ו׳

1FOR THESE TWO YEARS HATH THE FAMINE BEEN IN THE LAND. The reason why he mentioned to them what had transpired, which they themselves also knew, was to state that a land which has gone through two years of famine, in which the people had consumed all which they possessed, resulting in exceedingly high prices, and which was destined to experience five more years of famine, could offer them no sustenance whatsoever — had G-d not dispatched me before you.