Hadithcore
Riyad as-Salihin, 409

Abu Sa'id Al-Khudri (May Allah be pleased with him) reported:

Messenger of Allah (ﷺ) said, "How can I feel at ease when the Angel of the Trumpet, (Israfil) has put his lips to the Trumpet and is waiting for the order to blow it". He (ﷺ) perceived as if this had shocked his Companions, so he (ﷺ) told them to seek comfort through reciting: 'Hasbunallah wa ni'mal-Wakil <b>[Allah (Alone) is Sufficient for us, and He is the Best Disposer of affairs (for us)]</b>". <b>[At-Tirmidhi, who classified it as Hadith Hasan]</b>.

وعن أبي سعدي الخدرى، رضي الله عنه، قال‏:‏ قال رسول الله، صلى الله عليه وسلم ‏"‏كيف أنعم وصاحب القرن قد التقم ، واستمع الإذن متى يؤمر بالنفخ فينفخ‏"‏ فكأن ذلك ثقل على أصحاب رسول الله ، صلى الله عليه وسلم فقال لهم‏:‏‏"‏قولوا ‏:‏حسبنا الله ونعم الوكيل‏"‏ ‏(‏‏(‏رواه الترمذي وقال حديث حسن‏)‏‏)‏‏.‏

References1 variant
In-Book Reference
Introduction, Hadith 409
Sharh · explanationclick to expand
<b>Guidance from the Hadith:</b><br> 1) It was the Prophet’s guidance to give up living in comfort and luxury out of fear from the Day of Judgment.<br> 2) People are urged to seek help from Allah Almighty alone and hasten to do good deeds.<br> 3) It shows the Prophet’s compassion towards his Ummah and his fear that the Hour might come while they are alive, as he knew that it will come upon the most evil of people.<br> 4) If a person is troubled by something and he says, {Sufficient for us is Allah, and He is the best Disposer of affairs}, no harm will touch him, since remembrance of Allah makes hard things easy upon people.<br> <br> <br> <br> <b>Words in the Hadith:</b><br> The one with the trumpet: The angel assigned to blow the Horn, which is Isrāfil (may Allah exalt his mention).