بُلُوغُ الْمَرَامِ
Bulugh al-Maram 484
The Book of Prayer
وَعَنْهُ مَرْفُوعًا: { لَيْسَ فِي صَلَاةِ اَلْخَوْفِ سَهْوٌ } أَخْرَجَهُ اَلدَّارَقُطْنِيُّ بِإِسْنَادٍ ضَعِيفٍ [1] .
Narrated [Ibn 'Umar (RA)]: (This Hadith is) attributed to the Prophet (ﷺ) "There is no Sahw (prostration for forgetfulness) in the prayer in time of danger." [ad-Daraqutni reported it through a weak chain of narrators].
Sunnah.com reference: Book 2, Hadith 409