(1) باب صَلاَةِ الْمُسَافِرِينَ وَقَصْرِهَا
Ibn 'Abbas reported:
Allah has prescribed the prayer by the tongue of your Apostle (ﷺ) as two rak'ahs for the traveller, four for the resident, and one in danger. (PT)
Reference (PT): Sahih Muslim 687 b (PT)
In-book reference (PT): Book 6, Hadith 7 (PT)
USC-MSA web (English) reference(deprecated numbering scheme): Book 4, Hadith 1464 (PT)