Sahih Muslim , Book 6, Hadith 60 (In-Book) ⓘ

Ibn 'Abbas reported: The Messenger of Allah observed the noon and afternoon prayers together in Medina without being in a state of fear or in a state of journey. (Abu Zubair said: I asked Sa'id [one of the narrators] why he did that. He said: I asked Ibn 'Abbas as you have asked me, and he replied that he [the Holy Prophet] wanted that no one among his Ummah should be put to [unnecessary] hardship.)

وَحَدَّثَنَا أَحْمَدُ بْنُ يُونُسَ، وَعَوْنُ بْنُ سَلاَّمٍ، جَمِيعًا عَنْ زُهَيْرٍ، - قَالَ ابْنُ يُونُسَ حَدَّثَنَا زُهَيْرٌ، - حَدَّثَنَا أَبُو الزُّبَيْرِ، عَنْ سَعِيدِ بْنِ جُبَيْرٍ، عَنِ ابْنِ عَبَّاسٍ، قَالَ صَلَّى رَسُولُ اللَّهِ صلى الله عليه وسلم الظُّهْرَ وَالْعَصْرَ جَمِيعًا بِالْمَدِينَةِ فِي غَيْرِ خَوْفٍ وَلاَ سَفَرٍ ‏.‏ قَالَ أَبُو الزُّبَيْرِ فَسَأَلْتُ سَعِيدًا لِمَ فَعَلَ ذَلِكَ فَقَالَ سَأَلْتُ ابْنَ عَبَّاسٍ كَمَا سَأَلْتَنِي فَقَالَ أَرَادَ أَنْ لاَ يُحْرِجَ أَحَدًا مِنْ أُمَّتِهِ ‏.‏