A person, by the name of Muhajir, narrates as follows: “I had gone to Imam Sadiq (a.s) and said to him: “Such and such persons have sent you their salutations.” The Imam (a.s) responded in kind, whereupon I said: “They have also requested you to pray for them.” He (a.s) inquired: “What is their problem?” I said: “Mansur Dawaniqi has flung them into prison.”
He (a.s) asked: “What did they have to do with Mansur (that he hurled them into prison)?”
I replied: “They used to work for him and one day, in a fit of anger, he hurled them behind bars.”
The Imam (a.s) said: “But had I not prohibited them from working for him (an oppressive and unjust regime)? Such work entails great danger.” Having said this, the Imam (a.s) then prayed: “O’ Allah! Repel from them the evils and grant them deliverance.”
Muhajir says: “I returned from Mecca and inquired about my friends whereupon I was informed that they had been set free”” – (according to the dates, they had been released three days after the Imam (a.s) had prayed for them).( Shanidaniha-e-Tarikh, pg. 57; Mahajjah al-Baidha, vol. 3, pg. 256 )