What is the meaning of "v'Hu Avar"?
Rashi (to Bamidbar 22:26): He moved with the intention of going in front. 1
The Gemara in Pesachim 7b, borrowed the term when teaching us that the Berachah precedes the Mitzvah - 'Over l'Asiyaso.'
What was Yaakov thinking while he was bowing down?
Targum Yonasan: Yaakov went in front of [his family], praying to Hashem and asking Him for mercy, as he bowed to the ground 1 seven times....
Yayin ha'Tov (Chayei Sarah (3)): He did not spread out his hands and knees; it is not normal to do so to a person. (Or, this was in order to be prepared to spring into battle quickly, the moment he noticed that Esav was coming to fight. - EC)
Why does it say, "Ad Achiv," and not 'El Achiv'?
Ha'amek Davar: He did not go all the way, therefore Esav ran to him. 1
Ha'amek Davar: This is like "mi'Rosho v'Ad Raglav" (Vayikra 13:12) - it is Ad v'Lo Ad bi'Chlal (it does not include the head or the feet - Arachin 18b).
