I say, and with God's success: It is what the Prophet (peace be upon him) and the rightly guided caliphs consistently practiced, and they did not abandon it except once or twice for a specific reason. Thus, performing it is preferable to abandoning it, without prohibiting abandonment. It is of two types: the Sunnah of guidance: which is the confirmed Sunnah, that was practiced as a method in religion: such as congregational prayer, the call to prayer (adhan), and the establishment of prayer (iqamah), and similar acts. Its ruling is that abandoning it persistently without excuse leads to blame and dislike, and sin, though less than the sin of abandoning an obligatory act. The one who abandons it is blamed, and those who collectively abandon it are fought with weapons; because it is one of the signs of the religion, and persisting in abandoning it is a disregard for the religion, not because it is obligatory, according to Muhammad. Abu Yusuf said: fighting with weapons is only for those who persist in abandoning obligatory acts and duties, not for abandoning Sunnahs; to highlight the difference between obligatory acts and others. The Sunnah of extras: which is the non-confirmed Sunnah: such as the Sunnahs of the Prophet (peace be upon him) in his clothing, standing, sitting, grooming, and wearing shoes. Its ruling is that abandoning it does not lead to blame and dislike. Refer to: Al-Tawdeeh li Sadr al-Shari'ah, 2/257-263, Kashf al-Asrar, 1/84, Radd al-Muhtar, 1/102-103, 1/477, and Badai' al-Sanai', 1/24. And Umdat al-Ri'ayah 1: 62, and God knows best.