What blessing did Yaakov confer upon Pharaoh this time?
Rashi and Ramban: He blessed him that the Nile should rise to greet him and to water the land whenever he appeared. 1
Tosfos ha'Shalem (8:3, citing Moshav Zekenim): He showed appreciation that Pharaoh consented to let him return to his origin after the famine ends. 2
Which, from that moment on, it did. Ramban - The first time (47:7) was also a proper blessing; Yaakov now blessed him again when he requested to take leave.
Presumably, Yaakov did not do so, for he realized that he must fulfill "Ger Yihyeh Zar'echa" (15:13). Targum Yonasan (to 46:3) connotes that he knew this before descending. If so, why did he request? (PF)
QUESTIONS ON RASHI
Rashi writes: "Yaakov blessed [Pharaoh] - ... that the Nile should rise to his feet... and irrigate the land." Would Hashem perform such an overt miracle for an idolater? The Egyptians would likely deify Pharaoh!
Gur Aryeh: Yaakov's blessing was that, provided that Pharaoh would walk by the river regularly (as kings normally do), the Nile would always rise and water the land - at its proper time. This constituted a blessing, not an obvious miracle.
Rashi writes: "Yaakov blessed [Pharaoh] - ... that the Nile should rise to his feet... and irrigate the land." What is the symbolism in Yaakov giving this particular blessing?
Gur Aryeh (to 24:17): Blessing comes at the heels of a Tzadik (such as Yaakov); as such, the water sources increased in his merit. Also refer to 24:17:1.1:3.
