Musnad Ahmad 30:1111

The Messenger of Allah, may Allah bless him and grant him peace, said: "It was said to the Children of Israel: '{Enter the gate bowing and say: "Hittah" (relieve us of our sins)}' [Al-Baqarah: 58], 'We will forgive your sins.' But they altered it, and they entered the gate crawling on their posteriors, and they said: 'Habbah (a grain) in a hair.'"