رِيَاضُ الصَّالِحِينَ
Riyad as-Salihin 892
The Book of Greetings
The Excellence of Shaking Hands When Greeting Someone
وَعَنْ أَبِي ذَرٍّ، رَضِيَ اللَّهُ عَنْهُ، قَالَ: قَالَ لِي رَسُولُ اللَّهِ صَلَّى اللَّه عَلَيْهِ وَسَلَّمَ : لاَ تَحْقِرَنَّ مِنَ الْمَعْرُوفِ شَيْئًا، وَلَوْ أَنْ تلقي أَخَاكَ بِوَجْهٍ طَلْقٍ ((رَوَاهُ مُسْلِم)).
Abu Dharr (May Allah be pleased with him) reported: The Messenger of Allah (ﷺ) said to me, "Do not belittle any good deed, even your meeting with your brother (Muslim) with a cheerful face." [Muslim].
Riyad as-Salihin, 892