Parshas Vayishlach: Rav Moshe Leib MiSassov - A Tale Of Two Malachim
"VayeiAveik Ish Imo; A man wrestled with Yaakov," (Vayishlach 32:25). Rashi says this man was the Sar of Eisav. In Parshas Vayeishev when Yosef is looking for his brothers, it says, "Vayimtza'eihu Ish; A man found Yosef," and set him in the right direction. Rashi says that this man was Malach Gavriel. How does Rashi know that over here "man" means the Sar of Eisav and there it means Malach Gavriel?
The Pninim Al HaParsha brings from Rav Moshe Leib MiSassov that when the morning came Yaakov asked the "man" for a bracha after a grueling night of battle. He answered that he needed to go to Shamayim to say Shira to Hashem and didn't want to miss his chance. This attitude says Rav Moshe Leib can only come from the Malach of Eisav. However, the Malach who saw Yosef, although he no doubt also needed to go say Shira, he chose to postpone his tefila and take his chance of missing his opportunity to say Shira, when he saw a Yid who needed help. "This," says Rav Moshe Leib, "must be the Malach Gavriel."