The Holy Prophet (s.a.w.a.) informed – Certainly Allah helped me (in battles) through the angels who assumed the image of Ali bin Abi Talib (a.s.) so that they could strike terror in the hearts of the enemies.
Al-Fusool al-Mukhtarah p. 295 Madinah al-Ma'aajiz v 2 p 306 Behaar al-Anwaar v 41 p 100