Musnad Ahmad 27:1881

'Abd al-Razzaq narrated to us, Ma'mar informed us, from al-Zuhri, from Salim, from Ibn 'Umar, that the Messenger of Allah (may Allah bless him and grant him peace) passed by a man from the Ansar while he was admonishing his brother regarding shyness (haya'). The Messenger of Allah (may Allah bless him and grant him peace) said to him: "Leave him, for indeed shyness is from faith."