Hadith 4472

(حديث مرفوع) حَدَّثَنَا إِسْحَاقُ بْنُ يُوسُفَ الْأَزْرَقُ ، عَنْ عُبَيْدِ اللَّهِ يَعْنِي ابْنَ عُمَرَ ، عَنْ نَافِعٍ ، عَنِ ابْنِ عُمَرَ : أَنَّهُ كَانَ يَجْمَعُ بَيْنَ الصَّلَاتَيْنِ الْمَغْرِبِ وَالْعِشَاءِ ، إِذَا غَابَ الشَّفَقُ ، قَالَ : وَكَانَ رَسُولُ اللَّهِ صَلَّى اللَّهُ عَلَيْهِ وَسَلَّمَ " يَجْمَعُ بَيْنَهُمَا إِذَا جَدَّ بِهِ السَّيْرُ " .
Nafi' (may Allah have mercy on him) says that Sayyiduna Ibn Umar (may Allah be pleased with them both) used to combine Maghrib and Isha prayers after the twilight had disappeared, and he used to say that when the Prophet Muhammad (peace and blessings be upon him) was in a hurry to travel, he would also combine these two prayers.
Hadith Reference مسند احمد / مسند المكثرين من الصحابة / 4472
Hadith Grading حکم دارالسلام: إسناده صحيح، خ: 1805