(1) باب صَلاَةِ الْمُسَافِرِينَ وَقَصْرِهَا
Musa b. Salama Hudhali said:
I asked Ibn 'Abbas: How should I say prayer when I am in Mecca, and when I do not pray along with the Imam? He said: Two rak'ahs (of prayer) is the Sunnah of Abu'l-Qasim (ﷺ). (ID)
Reference (ID): Sahih Muslim 688 a (ID)
In-book reference (ID): Book 6, Hadith 8 (ID)
USC-MSA web (English) reference(deprecated numbering scheme): Book 4, Hadith 1465 (ID)