عَنِ ابْنِ عَبَّاسٍ رَضِيَ اللَّهُ عَنْهُمَا أَنَّ اللَّهَ عَزَّ وَجَلَّ فَرَضَ الصَّلَاةَ عَلَى لِسَانِ نَبِيِّكُمْ صَلَّى اللَّهُ عَلَيْهِ وَآلِهِ وَسَلَّمَ عَلَى الْمُقِيمِ أَرْبَعًا وَعَلَى الْمَسَافِرِ رَكْعَتَيْنِ وَعَلَى الْخَائِفِ رَكْعَةً
Sayyiduna Abdullah bin Abbas (may Allah be pleased with him) says that Allah Almighty made obligatory, through the tongue of the Noble Prophet (peace and blessings be upon him), four rak‘ahs upon the resident, two upon the traveler, and one upon the one in fear.