حَدَّثَنَا سُلَيْمَانُ بْنُ دَاوُدَ الْعَتَكِيُّ، حَدَّثَنَا حَمَّادٌ، حَدَّثَنَا أَيُّوبُ، عَنْ نَافِعٍ، أَنَّ ابْنَ عُمَرَ، اسْتُصْرِخَ عَلَى صَفِيَّةَ وَهُوَ بِمَكَّةَ فَسَارَ حَتَّى غَرَبَتِ الشَّمْسُ وَبَدَتِ النُّجُومُ فَقَالَ إِنَّ النَّبِيَّ صلى الله عليه وسلم كَانَ إِذَا عَجِلَ بِهِ أَمْرٌ فِي سَفَرٍ جَمَعَ بَيْنَ هَاتَيْنِ الصَّلاَتَيْنِ ‏.‏ فَسَارَ حَتَّى غَابَ الشَّفَقُ فَنَزَلَ فَجَمَعَ بَيْنَهُمَا ‏.‏

Narrated Abdullah ibn Umar: Ibn Umar was informed about the death of Safiyyah (the wife of the Prophet) when he was at Mecca. He proceeded till the sun set and the stars shined. He said: When the Prophet (PBUH) was in a hurry about something while on a journey, he would combine both these prayers. He proceed till twilight had disappeared. He then combined both of them (the prayers). Translation Not Available

Book reference: Sunan Abi Dawud Book 4 Hadith 1207
Web reference: Sunan Abi Dawud Book 4 Hadith 1203