she stood behind Him: At a banquet, people ate while lying on their sides around a low table, with their feet stretched out behind them. Because of this, the woman could not reach the head of Jesus to anoint him (to pour oil on him as a sign of honor), so she poured the perfume on his feet.
wipe them with her hair: In that culture, a woman normally kept her hair covered in public. Letting her hair down could bring shame and even give a husband reason for divorce. By wiping the feet of Jesus with her hair and kissing them, she showed deep respect and honor. She set aside normal social rules because she was so thankful.