Sayyiduna Malik bin Huwairith (may Allah be pleased with him) narrates: We came to the service of the Prophet Muhammad (peace and blessings be upon him); we were young men of similar age. We stayed with him for twenty days. When he realized that being away from our families was becoming difficult for us, he inquired from us about what we had left behind for our families. We informed him about this. The Prophet Muhammad (peace and blessings be upon him) was very kind and soft-hearted. The Prophet Muhammad (peace and blessings be upon him) said: "Return to your families. Teach them, command them, and perform the prayer as you have seen me perform the prayer. When the time for prayer comes, let one of you give the call to prayer (adhan), and the eldest among you should lead the prayer." Imam Ibn Hibban (may Allah have mercy on him) says: The statement of the Prophet Muhammad (peace and blessings be upon him), "Perform the prayer as you have seen me perform the prayer," is, in wording, an imperative form that includes everything the Prophet Muhammad (peace and blessings be upon him) used to do during his prayer. Among these, there are two things that have been specified by consensus, or have become specific due to a transmitted narration, so there is no harm for a person to leave them during prayer. And whatever has not been specified by consensus or by a transmitted hadith, then that is a mandatory command which is necessary for all addressed people, and it is not permissible to leave it under any circumstances.