أَخْبَرَنَا قُتَيْبَةُ، قَالَ حَدَّثَنَا أَبُو عَوَانَةَ، عَنْ يَحْيَى بْنِ أَبِي إِسْحَاقَ، عَنْ أَنَسٍ، قَالَ خَرَجْتُ مَعَ رَسُولِ اللَّهِ صلى الله عليه وسلم مِنَ الْمَدِينَةِ إِلَى مَكَّةَ فَلَمْ يَزَلْ يَقْصُرُ حَتَّى رَجَعَ فَأَقَامَ بِهَا عَشْرًا ‏.‏

It was narrated that Anas said: "I went out with the Messenger of Allah (PBUH) from Al-Madinah to Mekkah, and he continued to shorten his prayers, and he stayed there for ten days." Translation Not Available

Book Ref: Sunan An Nisai Book 15 Hadith 1438
Web Ref:  Sunan An Nisai Vol 2 Book 15 Hadith 1439