Bulugh al-Maram, Book 16, Hadith 1506 (English) ⓘ
Abu Dharr (RAA) narrated that the Messenger of Allah said: “Do not consider any act of goodness as being insignificant even if it is meeting your brother with a cheerful face.” Related by Muslim.
وَعَنْ أَبِي ذَرٍّ - رضى الله عنه - قَالَ: قَالَ رَسُولُ اَللَّهِ - صلى الله عليه وسلم -{ لَا تَحْقِرَنَّ مِنْ اَلْمَعْرُوفِ شَيْئًا, وَلَوْ أَنْ تَلْقَى أَخَاكَ بِوَجْهٍ طَلْقٍ } (1922) 2 - صحيح. رواه مسلم (2626).
also referenced under: Book 16, Hadith 1463 (In-Book)