Majma al-Zawaid — Hadith 18308

Sayyiduna Abdullah bin Abbas (may Allah be pleased with them both) reports concerning the saying of Allah Almighty: "When the Trumpet is blown." Sayyiduna Abdullah (may Allah be pleased with him) narrates that the Prophet (peace and blessings be upon him) said: How can I be at ease, when the angel in charge of the Horn (that is, the Trumpet) has put his mouth to the Horn, has bowed his forehead and is waiting for when he will be commanded so that he blows? The Companions of the Prophet (peace and blessings be upon him) submitted: What should we say? The Prophet (peace and blessings be upon him) said: Say: "Hasbunallahu wa ni'mal wakil, 'alallahi tawakkalna (Allah is sufficient for us and He is the best Disposer of affairs; in Allah alone we put our trust)."
Ahmad recorded it, and al-Tabarani recorded it in al-Mu'jam al-Awsat from that Companion in abridged form; its chain contains a narrator, Atiyyah al-Awfi, who is da'if (weak); he has been declared trustworthy, but weakly.