Caution: Translations of Quran and Ḥadīth may lead to possible misapplications and misinterpretations. This site is intended for students of sacred knowledge that are proficient in comprehending classical Arabic and have a strong foundation in Islamic sciences. Also note that religious injunctions rely on several aspects beyond what one may glean through reading individual aḥādīth.
Qurʾān Bukhārī Muslim Nasāʾī Abū Dāwūd Tirmidhī Ibn Mājah Mālik Aḥmad Dārimī Ḥākim Ibn Ḥibbān Ṭabarānī Nasāʾī's Kubrá Bayhaqī al-Luʾluʾ wa-al-Marjān Ibn Rajab's Fifty Riyāḍ al-Ṣāliḥīn Aḥmad's Zuhd Suyūṭī
ahmad:2632 – ʿAffān > Shuʿbah > Qatādah > Mūsá b. Salamah > Saʾalt Ibn ʿAbbās > Innī Akūn Bimakkah Fakayf Uṣallī

[Machine] I said, "I am in Mecca, so how should I pray?" He replied, "Perform two units of the Sunnah prayer, O Abu Al-Qasim. Peace be upon him."  

أحمد:٢٦٣٢ – حَدَّثَنَا عَفَّانُ حَدَّثَنَا شُعْبَةُ قَالَ قَتَادَةُ أَنْبَأَنِي قَالَ سَمِعْتُ مُوسَى بْنَ سَلَمَةَ قَالَ سَأَلْتُ ابْنَ عَبَّاسٍ قَالَ

قُلْتُ إِنِّي أَكُونُ بِمَكَّةَ فَكَيْفَ أُصَلِّي؟ قَالَ رَكْعَتَيْنِ سُنَّةَ أَبِي الْقَاسِمِ ﷺ  

See similar narrations below:

Collected by Nasāʾī, Nasāʾī's Kubrá
nasai:1443 – Muḥammad b. ʿAbd al-Aʿlá Fī Ḥadīthih > Khālid b. al-Ḥārith > Shuʿbah > Qatādah > Mūsá And Hū Ibn Salamah

"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.'"  

النسائي:١٤٤٣ – 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 ﷺ  

nasai-kubra:1914 – Muḥammad b. ʿAbd al-Aʿlá Fī Ḥadīthih > Khālid b. al-Ḥārith > Shuʿbah > Qatādah > Mūsá And Hū Ibn Salamah

"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.'" (Using translation from Nasāʾī 1443)  

الكبرى للنسائي:١٩١٤ – أَخْبَرَنَا مُحَمَّدُ بْنُ عَبْدِ الْأَعْلَى فِي حَدِيثِهِ عَنْ خَالِدِ بْنِ الْحَارِثِ قَالَ حَدَّثَنَا شُعْبَةُ عَنْ قَتَادَةَ قَالَ سَمِعْتُ مُوسَى وَهُوَ ابْنُ سَلَمَةَ قَالَ

قُلْتُ لِابْنِ عَبَّاسٍ كَيْفَ أُصَلِّي بِمَكَّةَ إِذَا لَمْ أُصَلِّ فِي جَمَاعَةٍ؟ قَالَ «رَكْعَتَيْنِ سُنَّةَ أَبِي الْقَاسِمِ ﷺ»