His statement: {Alif-Lam-Mim-Sad}. Al-Hasan used to say: "I do not know the interpretation of {Alif-Lam-Mim-Sad} and similar letters of the alphabet found at the beginning of the Surahs." However, a group of the Salaf (early predecessors) used to say: "They are the names of the Surahs and their openers."