صحيح ابن خزيمه
Sahih Ibn Khuzaymah
جماع أبواب قيام المأمومين خلف الإمام وما فيه من السننChapters on Followers Standing Behind the Imam
(130) بَابُ إِبَاحَةِ ائْتِمَامِ الْمُصَلِّي فَرِيضَةً بِالْمُصَلِّي نَافِلَةً،130| Chapter on the permissibility of following someone praying a voluntary prayer while one is praying an obligatory prayer
Hadith Q1633
ضِدَّ قَوْلِ مَنْ زَعَمَ مِنَ الْعِرَاقِيِّينَ أَنَّهُ غَيْرُ جَائِزٍ أَنْ يَأْتَمَّ الْمُصَلِّي فَرِيضَةً بِالْمُصَلِّي نَافِلَةً.
Contrary to the statement of those Iraqi scholars who say that it is not permissible for one performing an obligatory prayer to follow one performing a supererogatory (nafl) prayer.
