A ḥadīṯ ascribed to Muḥammad b. Isḥāq (d. 150/767) reproduces a pre-Islamic Syriac text, namely, the Horarium of the Testament of Adam. Therein Adam enumerates the times at which each creature praises the Lord. At least one scholar uses the text in his gloss of the Qur’anic verse Q. 22:18, wherein God is said to cause several beings to prostrate to him. A comparison between the different versions of the Testament of Adam helps us identify the specificities of its Muslim rendering. Despite this attempt to adapt the text to the Muslim religious corpus, its diffusion remained limited, as far as our sources can tell.