Jacob received the name "Israel" because he wrested in the night with God (an angel of God, cf. Hosea 12:4). As the sun began to rise, the angelic being touched the sinew of his thigh (גיד הנשה). This "touch" crippled Jacob and he apparently walked with a limp for the rest of his life. Jacob's miraculous wound is the etiological reason for why Israelites do not eat the meat around the sciatic nerve on any animal.