بُلُوغُ الْمَرَامِ
Bulugh al-Maram 1463
The Comprehensive Book
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 } [1]
Abu Dharr (RAA) narrated that the Messenger of Allah (ﷺ) 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.
Arabic/English book reference: Book 16, Hadith 1506