"And if you slain in the Way of Allah or you die..."
(Aale Imraan: 157)
Imam Mohammad Baqir (as) said about the above verse:
"Slain in the way of Allah is 'in the way of Ali (as) and his descendants (as)'..."
[Ref: Bihar ul-Anwar, V.56, P.41, T.8; Muntakhabul Basair, p.111]