Genesis 47:10

ויברך יעקב AND JACOB BLESSED [PHARAOH] — i.e. he gave him the salutation of peace as is usual for all who take their leave of princes — they salute them and depart. A Midrash however understands this more literally and asks, “What was the blessing with which he blessed him? That the waters of the Nile might rise at his approach Because Egypt does not drink (is not irrigated by) rain-water, but the waters of the Nile rise and irrigate it. And from the time when Jacob blessed him and henceforth, whenever Pharaoh came to the Nile it rose at his coming, overflowed its banks and watered the land. Thus it is stated in Tanchuma Yashan 4:2:26 to נשא.

וַיְבָ֥רֶךְ יַעֲקֹ֖ב אֶת־פַּרְעֹ֑ה וַיֵּצֵ֖א מִלִּפְנֵ֥י פַרְעֹֽה׃

And Ya῾aqov blessed Par῾o, and went out from before Par῾o.