Amr bin Maymoon Al-Awdi narrates: Sayyiduna Mu'adh bin Jabal (may Allah be pleased with him) came to us in Yemen. The Prophet (peace and blessings of Allah be upon him) had sent him to us. I heard his takbeer with the Fajr prayer. He was a person with a soft voice, and love for him settled in my heart. I parted from him only when I buried him in Syria. Then, after him, I looked for the greatest scholar among the people, so I presented myself to the service of Sayyiduna Abdullah bin Mas'ud (may Allah be pleased with him). I remained with him until he also passed away. He said to me: The Prophet (peace and blessings of Allah be upon him) said: "What will be your condition when such rulers are imposed over you who will perform the prayer outside of its prescribed times?" I said: O Messenger of Allah! If I find them, what do you instruct me to do regarding this? The Prophet (peace and blessings of Allah be upon him) said: "Perform the prayer at its prescribed time, and make your prayer with them a supererogatory (nafl) prayer." (Imam Ibn Hibban, may Allah have mercy on him, says:) The statement of the Prophet (peace and blessings of Allah be upon him), "Make your prayer with them a nafl prayer," is the greatest evidence that the prayer of a person performing a nafl prayer behind someone performing a fard prayer is permissible. This is contrary to the view of the one who has ruled otherwise. In this, there is also evidence that nafl prayer can be performed in congregation.