حَدَّثَنَا مَحْمُودُ بْنُ غَيْلاَنَ، حَدَّثَنَا وَكِيعٌ، حَدَّثَنَا سُفْيَانُ، عَنْ أَبِي إِسْحَاقَ، عَنِ الْمُهَلَّبِ بْنِ أَبِي صُفْرَةَ، عَمَّنْ سَمِعَ النَّبِيَّ صلى الله عليه وسلم يَقُولُ " إِنْ
بَيَّتَكُمُ الْعَدُوُّ فَقُولُوا: حم لاَ يُنْصَرُونَ "
Narrated Al-Muhallab bin Abi Sufrah:
From one who heard the Prophet (ﷺ) saying: "If you suffer a surprise attack from the enemy then say: 'Ha Min, they will not be victorious.'"
[Abu 'Eisa said:] There is something on this topic from Salamah bin Al-Akwa'. This is how some of them reported it from Abu Ishaq, the same as the narration of Ath-Thawri. And it has been reported from him, from Al-Muhallab bin Abi Sufrah from the Prophet (ﷺ) in Mursal form.
Reported by At-Tirmidhi (No. 1682).