Sahih al-Bukhari 350

Arabic

حَدَّثَنَا عَبْدُ اللَّهِ بْنُ يُوسُفَ، قَالَ أَخْبَرَنَا مَالِكٌ، عَنْ صَالِحِ بْنِ كَيْسَانَ، عَنْ عُرْوَةَ بْنِ الزُّبَيْرِ، عَنْ عَائِشَةَ أُمِّ الْمُؤْمِنِينَ، قَالَتْ ‏ "‏ فَرَضَ اللَّهُ الصَّلاَةَ حِينَ فَرَضَهَا رَكْعَتَيْنِ رَكْعَتَيْنِ فِي الْحَضَرِ وَالسَّفَرِ، فَأُقِرَّتْ صَلاَةُ السَّفَرِ، وَزِيدَ فِي صَلاَةِ الْحَضَرِ ‏"‏‏.‏

Translation

Narrated `Aisha:the mother of believers: Allah enjoined the prayer and when He enjoined it, it was two rak`at only (in every prayer) both when in residence or on journey. Then the prayers offered on journey remained the same, but (the rak`at of) the prayers for non-travelers were increased

Authenticity

Sahih

Reference