The Book of Virtue, Enjoining Good Manners, and Joining of the Ties of Kinship
Ṣaḥīḥ Muslim 6589
الْمُسْلِمُونَ كَرَجُلٍ وَاحِدٍ إِنِ اشْتَكَى عَيْنُهُ اشْتَكَى كُلُّهُ وَإِنِ اشْتَكَى رَأْسُهُ اشْتَكَى كُلُّهُ
al-muslimūna karajulin wāḥidin ini āshtakā ʿaynuhu āshtakā kulluhu wa-ini āshtakā raʾsuhu āshtakā kulluhu
Transliteration generated from the Arabic vowel marks
The full narration
Nu'man b. Bashir reported that Muslims are like one body of a person; if the eye is sore, the whole body aches, and if the head aches, the whole body aches
Source
Ṣaḥīḥ Muslim · 6589
Ṣaḥīḥ