And the explanation of the evidence that only five prayers are obligatory. All prayers besides these five are voluntary. Except for the five prayers, no other prayer is obligatory.

It is narrated from Sayyiduna Talhah bin Ubaidullah (may Allah be pleased with him) that a Bedouin came to the service of the Prophet (peace and blessings of Allah be upon him) while his hair was disheveled. He said, "O Messenger of Allah (peace and blessings of Allah be upon him), tell me what Allah has made obligatory upon me from the prayers?" The Prophet (peace and blessings of Allah be upon him) said: "Five prayers, unless you perform any voluntary prayer." He said, "Tell me what Allah has made obligatory upon me from zakat?" So the Messenger of Allah (peace and blessings of Allah be upon him) informed him of the Islamic rulings regarding (zakat). He said, "By Him Who has honored you, I will not do any voluntary act; I will neither decrease anything from what Allah has made obligatory upon me." The Messenger of Allah (peace and blessings of Allah be upon him) said: "By his father, if he has spoken the truth, he has succeeded." Or he said: "By his father, if he has spoken the truth, he will enter Paradise."