حَدَّثَنَا مُحَمَّدُ بْنُ عَبْدِ الأَعْلَى، فِي حَدِيثِهِ عَنْ خَالِدِ بْنِ الْحَارِثِ، قَالَ حَدَّثَنَا شُعْبَةُ، عَنْ قَتَادَةَ، قَالَ سَمِعْتُ مُوسَى، - وَهُوَ ابْنُ سَلَمَةَ - قَالَ قُلْتُ لاِبْنِ عَبَّاسٍ كَيْفَ أُصَلِّي بِمَكَّةَ إِذَا لَمْ أُصَلِّ فِي جَمَاعَةٍ قَالَ رَكْعَتَيْنِ سُنَّةَ أَبِي الْقَاسِمِ صلى الله عليه وسلم ‏.‏

It was narrated that Qatadah said: "I heard Muas- bin Salamah-say: 'I said to Ibn 'Abbas: How should I pray in Makkah if I do not pray in congregation? He said: Two rak'ahs, the sunnah of Abu Al-Qasim.'" Translation Not Available

Book reference: Sunan An Nisai Book 15 Hadith 1443
Web reference: Sunan An Nisai Volume 2 Book 15 Hadith 1444