^Ernst, Carl W. How to Read the Qurʼan: A New Guide, with Select Translations. Chapel Hill: University of North Carolina, 2011. Print.
^The Message of the Quran, M. Asad, 1982, Introduction Surah Ta-Ha. As is the case with the preceding surah, its position in the chronology of Qur'anic revelation is not difficult to establish. Despite the vague assertions of some of the later authorities that it was revealed during the last phase (or even in the last year) of the Prophet's sojourn in Mecca, we know for certain that it was fully known to his Companions as early as the sixth year of his mission (that is, at least seven years before he left Mecca for Medina): for it was this very surah which at that period accidentally fell into the hands of 'Umar ibn al-Khattab - who until then had been a bitter opponent of the Prophet - and caused his conversion to Islam (Ibn Sad 111/1, 191 ff.)
