Sahih al-Bukhari 1081
Sahih al-Bukhari · Book 18: Shortening the Prayers (At-Taqseer) · For what period of stay one should offer shortened prayers
Narrated Yahya bin 'Is-haq:
حَدَّثَنَا أَبُو مَعْمَرٍ ، قَالَ حَدَّثَنَا عَبْدُ الْوَارِثِ ، قَالَ حَدَّثَنَا يَحْيَى بْنُ أَبِي إِسْحَاقَ ، قَالَ سَمِعْتُ أَنَسًا ، يَقُولُ خَرَجْنَا مَعَ النَّبِيِّ صلى الله عليه وسلم مِنَ الْمَدِينَةِ إِلَى مَكَّةَ، فَكَانَ يُصَلِّي رَكْعَتَيْنِ رَكْعَتَيْنِ حَتَّى رَجَعْنَا إِلَى الْمَدِينَةِ. قُلْتُ أَقَمْتُمْ بِمَكَّةَ شَيْئًا قَالَ أَقَمْنَا بِهَا عَشْرًا.
I heard Anas saying, "We traveled with the Prophet (ﷺ) from Medina to Mecca and offered two rak`at (for every prayer) till we returned to Medina." I said, "Did you stay for a while in Mecca?" He replied, "We stayed in Mecca for ten days."