Musar zu Bereschit 1:15

What all this has to do with Samael injuring the כף ירך יעקב, the thigh joint of Jacob, is simple. Our sages say on 32,26: וירא כי לא יוכל לו, ויגע בכף ירכו ותקע כך ירך יעקב, that the thigh joint of Jacob refers to the later descendants who experienced the harsh decrees by the various nations who were their hosts in exile. When the Hasmoneans overcame the Greeks, they reversed this injury, i.e. the כף became a פך a cruse of oil. What had been a vulnerable part of Jacob's ירך now became the solid basis of the candelabra, ירך מנורה.