Al-Adab Al-Mufrad, Book 42, Hadith 1033 (English) ⓘ
Abu Jamra said, "I heard Ibn 'Abbas say when he was greeted, 'And upon you and the mercy of Allah.'"
حَدَّثَنَا حَامِدُ بْنُ عُمَرَ، قَالَ: حَدَّثَنَا أَبُو عَوَانَةَ، عَنْ أَبِي جَمْرَةَ، سَمِعْتُ ابْنَ عَبَّاسٍ إِذَا سُلِّمَ عَلَيْهِ يَقُولُ: وَعَلَيْكَ، وَرَحْمَةُ اللهِ.
also referenced under: Hadith 1033 (Reference) & Book 42, Hadith 70 (In-Book)