יהיו שבע שני רעב. יהיו לשון תפלה הוא שמן הדין הי' להיות מ"ב שנים רעב במצרים כיצד שבע דפרות ושבע דשבלים דחלום. וכן בספור. וכן דהגדה מפי יוסף שבע דפרות ושבע דשבלים הרי מ"ב. ועל ידי תפלת יוסף נחסרו עד שבעה בא יעקב ונחסרו עד ב' הרי מ' נחסרו ונפרעו להם בימי ירמיה דכתיב והיה מצרים לשמה מ' שנה: יהיו שבע שני רעב, “will be seven consecutive years of famine.” The word יהיו should be understood as a prayer by Joseph, who was aware that actually 42 years of famine had been decreed for Egypt. How did Joseph know this? You will note that the number שבע appeared in Pharaoh’s dream 6 times. Twice seven when Pharaoh had the dream, once with the cows, once with the ears of corn. The same was repeated when he related his dream to his interpreters. It was repeated again when he related the dream to Joseph. Joseph’s prayer achieved that the 42 years which had been decreed were shrunk to only seven years. The arrival of Joseph’s father Yaakov in Egypt and his blessing to Pharaoh reduced the famine further so that it lasted only two years. The 40 years that were chopped off the decree did not disappear but were “paid back” to Egypt in later years as we know from Jeremiah that Egypt experienced 40 years of total drought predicted by that prophet. (Ezekiel 29,9 and 12)