If a person intentionally or on account of culpable ignorance (al‑jahl al‑taqṣīrī) does not recite one of the words of Sūrat al-Ḥamd or the other surah, or in place of one of the letters he utters another letter – for example, instead of ‘ض’, he says ‘ذ’ or ‘ز’, or he does not correctly observe the fatḥah [ــَـ] and kasrah [ــِـ] of words such that his recitation is considered wrong, or he does not pronounce with tashdīd [ــّـ] [when he is supposed to] – then in these cases, his prayer is invalid.