It was narrated from Ibn ‘Abbas that the Messenger of Allah ﷺ stayed in Makkah for fifteen nights during the year of the Conquest, (during which time) he shortened his prayer.
أَنَّ رَسُولَ اللَّهِ ﷺ أَقَامَ بِمَكَّةَ عَامَ الْفَتْحِ خَمْسَ عَشْرَةَ لَيْلَةً يَقْصُرُ الصَّلاَةَ