رِيَاضُ الصَّالِحِينَ
Riyad as-Salihin 476
The Book of Miscellany
Excellence of Leading an Ascetic Life, and Virtues of Simple Life
وَعَنْ سَهْلِ بْنِ سَعْدٍ الساعدى، رَضِيَ اَللَّهُ عَنْهُ، قَالَ: قَالَ رَسُولُ اللَّهِ، صَلَّى اللَّه عَلَيْهِ وَسَلَّمَ : لَوْ كَانَتِ الدُّنْيَا تَعْدِلُ عِنْدَ اللَّهِ جَنَاحَ بَعُوضَةٍ مَا سَقَى كَافِرًا مِنْهَا شَرْبَةَ مَاءٍ ((رَوَاهُ التِّرْمِذِيُّ . وَقَالَ حَدِيثٌ حَسَن صَحِيح))
Sahl bin Sa'd (May Allah be pleased with him) reported: Messenger of Allah (ﷺ) said, "Were this world worth a wing of mosquito, He would not have given a drink of water to an infidel." [At- Tirmidhi, who classified it as Hadith Hasan Sahih].
Riyad as-Salihin, 476