Musannaf Ibn Abi Shaybah

Hazrat Bassam says that I asked Hazrat Abu Ja'far whether prayer should be performed behind the Imams. He replied, "Pray with them, because we also pray with them. Hazrat Hasan and Hazrat Husayn used to pray behind Marwan." I said to him, "People think that this was 'taqiyyah' (dissimulation)." He replied, "How can that be? Hazrat Hasan bin Ali (may Allah be pleased with him) used to criticize Marwan openly on the pulpit in front of him, until he became the governor."