194عَلىٰ قَلبِكَ لِتَكونَ مِنَ المُنذِرينَMuhammad Asadupon thy heart, [O Muhammad]1 so that thou mayest be among those who preachAccording to almost all the classical commentators, the expression ar-ruh al-amin (lit., "the faithful [or "trustworthy"] spirit") is a designation of Gabriel, the Angel of Revelation, who, by virtue of his purely spiritual, functional nature, is incapable of sinning and cannot, therefore, be other than utterly faithful to the trust reposed in him by God (cf. 16:50). On the other hand, since the term ruh is often used in the Qur'an in the sense of "divine inspiration" (see surah 2, note 71, and surah 16, note 2), it may have this latter meaning in the above context as well, especially tn view of the statement that it had "alighted from on high upon the heart" of the Prophet.