בִּ֖י אֲדֹנָ֑י מָ֣ה אֹמַ֔ר אַ֠חֲרֵי אֲשֶׁ֨ר הָפַ֧ךְ יִשְׂרָאֵ֛ל עֹ֖רֶף לִפְנֵ֥י אֹיְבָֽיו׃
Bitte, Herr! was soll ich sagen, nachdem Israel den Rücken gewandt vor seinen Feinden?
Bereishit Rabbah
It teaches that he gave him the strength of a lion and the audacity of its cubs.