(25) Chapters on Hajj Rituals
كتاب المناسك
(39) Chapter: Tawaf for one performing Qiran
(39) باب طَوَافِ الْقَارِنِ
Sunan Ibn Majah 2975 
It was narrated from Ibn ‘Umar that the Messenger of Allah (ﷺ) said:
“Whoever enters Ihram for Hajj and ‘Umrah, one Tawaf is sufficient for both, and he should not exit Ihram until he has completed his Hajj, when he should exit Ihram for both.”
حَدَّثَنَا مُحْرِزُ بْنُ سَلَمَةَ، حَدَّثَنَا عَبْدُ الْعَزِيزِ بْنُ مُحَمَّدٍ، عَنْ عُبَيْدِ اللَّهِ، عَنْ نَافِعٍ، عَنِ ابْنِ عُمَرَ، أَنَّ رَسُولَ اللَّهِ ـ صلى الله عليه وسلم ـ قَالَ ‏ "‏ مَنْ أَحْرَمَ بِالْحَجِّ وَالْعُمْرَةِ كَفَى لَهُمَا طَوَافٌ وَاحِدٌ وَلَمْ يَحِلَّ حَتَّى يَقْضِيَ حَجَّهُ وَيَحِلَّ مِنْهُمَا جَمِيعًا ‏"‏ ‏.‏
Grade :  Sahih (Darussalam)
Reference : Sunan Ibn Majah 2975
In-book reference : Book 25, Hadith 94
English translation : Vol. 4, Book 25, Hadith 2975