Page 2 of 7
There are two of the traditional 613 commandments found within the book of Genesis. The first is in parashah Bereshit. The second is in this week's parashah and is the traditional commandment "do not eat the sinew of the thigh" found in Genesis 32:32. The passage does not actually record G-d delivering a commandment. Instead we find the brief mention of a tradition of the son's of Israel to honor their forefather Ya'akov by not eating the sinew of the thigh of kosher animals.
This relates back to the story of Ya'akov wrestling with G-d/the angel/a man. At the conclusion of the event, Ya'akov was touched in the socket of his thigh so that it was dislocated (Genesis 32:25).