Abu Ubaid al-Qasim ibn Sallam al-Khurasani al-Harawi (Arabic: أبو عبيد القاسم بن سلاّم الخراساني الهروي, romanized: Abū ‘Ubayd al-Qāsim ibn Sallām al-Khurāsānī al-Harawī; c. 770–838) was an Arab philologist and the author of many standard books on lexicography, Qur’anic sciences, hadith, and fiqh.
He left his native town and studied philology at the Basra school under many famous scholars such as al-Asmaʿi (d. 213/828), Abu ʿUbayda (d. c.210/825), and Abu Zayd al-Ansari (d. 214 or 215/830–1), and at the Kufa school under Abu ʿAmr al-Shaybani (d. c.210/825), al-Kisaʾi (d. c.189/805), and others.
He was the first to develop a recorded science for tajwid, giving the rules of tajwid names and putting it into writing in his book called al-Qirā'āt.
[2] He made the reality, transmitted through reciters of every generation, a science with defined rules, terms, and enunciation.
[3][4] He wrote extensively on the originally revealed, but then abrogated, verses from the Qur’an.