'Hair of His Head' in the Bible

Howbeit, the hair of his head began to grow again after that he was shorn.

But the people said unto Saul, "Shall Jonathan die, which hath so mightily helped Israel? God forbid. As truly as the LORD liveth, there shall not one hair of his head fall to the ground: for he hath wrought with God this day." And so the people delivered Jonathan, that he died not.