Abu ?ayyan Athir ad-Din al-Gharna?i (Arabic: ????? ??????? ?????? ??????? ???????????????, November 1256 – July 1344), whose full name is Mu?ammad ibn Yusuf bin ‘Ali ibn Yusuf ibn Hayyan (Arabic: ???????? ???? ?????? ???? ?????? ???? ?????? ???? ????????), sometimes called Ibn Hayyan, was a celebrated commentator on the Quran and foremost Arabic grammarian of his era.
His magnum opus Tafsir al-Bahr al-Muhit (Explanation of the Ocean) is the most important reference on Qur'anic expressions and the issues of grammar, vocabulary, etymology and the transcriber-copyists of the Holy Qur'an.
Quite exceptionally for a linguist of Arabic of his day was his strong interest in non-Arabic languages.
He wrote several works of comparative linguistics for Arabic speakers, and gives extensive comparative grammatical analysis and explanation.