Shaikh Sadooq narrates a narration in his book “Aitqadat”
” Imam Jafar narrates that whoever doubts in the disbelief of our enemies and the ones who oppressed us , he is himself a disbeliever.
Ameer ul Momineen (i.e Ali) said : I have been oppressed since my birth, so much so that when Aqeel would feel pain in his eyes, he would say : first put the medicine in the eyes of Ali, than I will allow it to be put in my eyes. Than the medicine would be put in my eyes, even though I would not feel pain in my eyes at all “
Aitqadat , p. 107
Do I need to explain what he means?