Abū Alī Muḥammad ibn al-Mustanīr (أبو علي محمد بن المستنير), known as Quṭrub the Grammarian of al-Baṣrah, was a poet, a scientist, a scholar of Qur'anic exegesis (tafsir) and the leading philologist and linguist of his time. He wrote on a wide field of subjects and authored the first Kitāb al-Muthalath ('Ternary'), of which several later and extended versions were produced. He died in 821/22 (206 AH).