Imam Muhammad Baqir (a.s.) it is mentioned that he said: The believer would intercede for his neighbour who would not have even a single good deed to his credit. He would say: O my Lord, my neighbour removed my hardships. Thus he would be allowed to intercede for him. Allah, Blessed and High be He, would say: I am your Lord, and more capable of rewarding him than you. Then He will make him enter Paradise while he won’t be having a single good deed in his account. And the least that a believer would intercede for is thirty persons. At that time the inmates of Hell would say: “So we have no intercessors, nor a true friend.” (Surah Shoara (26): 100)
Behaar al-Anwaar v 8 p 56