Imam Ali b. Moosa al-Reza (a.s.) narrated on the authority of his immaculate forefathers (a.s.) that the Holy Prophet (s.a.w.a.) said to Imam Ali (a.s.), ‘O Ali! You are the oppressed one after me. Woe be to whoever oppresses you! Blessed be whoever follows you and does not prefer anyone else over you…’
Oyoon Akhbaar al-Reza (a.s.) chap 28 trad 58