Commentary for Genesis 45:6

כי זה שנתים הרעב means FOR THESE TWO YEARS OF FAMINE have passed of the years of famine that are to come in the land.

FOR 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.

כי זה שנתים הרעב, “for these two years of famine, etc.” He reminded them of the years of famine that had already passed, and that they had already consumed all their reserves although there were five more years of famine in store for the country. How could they have hoped to survive the next five years if G’d in His providence had not sent Joseph ahead of them to Egypt in order to be able to provide for his family?