Jami` at-Tirmidhi, Hadith 2320 ⓘ
Sahl bin Sa'd narrated that the Messenger of Allah (s.a.w) said: "If the world to Allah was equal to a mosquito's wing, then He would not allow the disbeliever to have a sip of water from it."
حَدَّثَنَا قُتَيْبَةُ، حَدَّثَنَا عَبْدُ الْحَمِيدِ بْنُ سُلَيْمَانَ، عَنْ أَبِي حَازِمٍ، عَنْ سَهْلِ بْنِ سَعْدٍ، قَالَ قَالَ رَسُولُ اللَّهِ صلى الله عليه وسلم " لَوْ كَانَتِ الدُّنْيَا تَعْدِلُ عِنْدَ اللَّهِ جَنَاحَ بَعُوضَةٍ مَا سَقَى كَافِرًا مِنْهَا شَرْبَةَ مَاءٍ " . وَفِي الْبَابِ عَنْ أَبِي هُرَيْرَةَ . قَالَ أَبُو عِيسَى هَذَا حَدِيثٌ صَحِيحٌ غَرِيبٌ مِنْ هَذَا الْوَجْهِ .
also referenced under: Book 36, Hadith 17 (In-Book) & Volume 4, Book 34, Hadith 2320 (DarusSalam)