as to which of you is best in deeds.”
Al-Mulk 67:2

He said: “The most sincere and the most correct.” He was asked: “O Abū ‘Alī, what does ‘the most sincere and the most correct’ mean?” He replied: “If a deed is correct but not sincere, it will not be accepted; and if it is sincere but not correct, it will not be accepted, until it is both sincere and correct. Sincerity means that it is done for Allah, and correctness means that it accords with the Sunnah.”

Ibn Shāhīn and al-Lālakā’ī narrated that Sa‘īd ibn Jubayr said: “No speech is accepted without action; neither speech nor action is accepted without intention; and neither speech, action, nor intention is accepted unless it accords with the Sunnah.” They also narrated a similar statement from al-Hasan al-Basrī, though the wording narrated from al-Hasan is “is not sound” rather than “is not accepted.”

This refutes those who consider mere speech sufficient—the Murji’ah. He thus stated that both speech and action are indispensable, since faith consists of speech and action: both are necessary, as we have explained at length elsewhere, where we made clear that mere