'I heard Imam al-Rida (AS) say: ''Alif, lam, mim. Do people imagine that they will be left off (on their own) saying: We believe!? and they will not be tried?, and he then asked me, 'What is trial?' I said, may my soul be sacrificed for you, what I know is that it is to be tested in religion.' He said, 'They [the believers] will be tried the way gold is tried', he then said, 'They will be purified the way gold is purified.'