وَحَدَّثَنَا أَبُو بَكْرِ بْنُ أَبِي شَيْبَةَ، وَأَبُو كُرَيْبٍ قَالاَ حَدَّثَنَا أَبُو مُعَاوِيَةَ، ح وَحَدَّثَنَا أَبُو كُرَيْبٍ، وَأَبُو سَعِيدٍ الأَشَجُّ - وَاللَّفْظُ لأَبِي كُرَيْبٍ - قَالاَ حَدَّثَنَا وَكِيعٌ، كِلاَهُمَا عَنِ الأَعْمَشِ، عَنْ حَبِيبِ بْنِ أَبِي ثَابِتٍ، عَنْ سَعِيدِ بْنِ جُبَيْرٍ، عَنِ ابْنِ عَبَّاسٍ، قَالَ جَمَعَ رَسُولُ اللَّهِ صلى الله عليه وسلم بَيْنَ الظُّهْرِ وَالْعَصْرِ وَالْمَغْرِبِ وَالْعِشَاءِ بِالْمَدِينَةِ فِي غَيْرِ خَوْفٍ وَلاَ مَطَرٍ ‏.‏ فِي حَدِيثِ وَكِيعٍ قَالَ قُلْتُ لاِبْنِ عَبَّاسٍ لِمَ فَعَلَ ذَلِكَ قَالَ كَىْ لاَ يُحْرِجَ أُمَّتَهُ ‏.‏ وَفِي حَدِيثِ أَبِي مُعَاوِيَةَ قِيلَ لاِبْنِ عَبَّاسٍ مَا أَرَادَ إِلَى ذَلِكَ قَالَ أَرَادَ أَنْ لاَ يُحْرِجَ أُمَّتَهُ ‏.‏

Ibn 'Abbas reported that the Messenger of Allah (PBUH) combined the noon prayer with the afternoon prayer and the sunset prayer with the 'Isha' prayer in Medina without being in a state of danger or rainfall. And in the hadith transmitted by Waki' (the words are): " I said to Ibn 'Abbas: What prompted him to do that? He said: So that his (Prophet's) Ummah should not be put to (unnecessary) hardship." And in the hadith transmitted by Mu'awiya (the words are):" It was said to Ibn 'Abbas: What did he intend thereby? He said he wanted that his Ummah should not be put to unnecessary hardship." Translation Not Available

Book Ref: Sahih Muslim Book 6 Hadith 1520
Web Ref:  Sahih Muslim Book 4 Hadith 705 d