The Book of Virtue, Enjoining Good Manners, and Joining of the Ties of Kinship
Ṣaḥīḥ Muslim 6588
الْمُؤْمِنُونَ كَرَجُلٍ وَاحِدٍ إِنِ اشْتَكَى رَأْسُهُ تَدَاعَى لَهُ سَائِرُ الْجَسَدِ بِالْحُمَّى وَالسَّهَرِ
al-muʾminūna karajulin wāḥidin ini āshtakā raʾsuhu tadāʿā lah sāʾiru al-jasadi bi-l-ḥummā wa-as-sahari
Transliteration generated from the Arabic vowel marks
The full narration
Nu'man b. Bashir reported Allah's Messenger (ﷺ) as saying:The believers are like one person; if his head aches, the whole body aches with fever and sleeplessness
Source
Ṣaḥīḥ Muslim · 6588
Ṣaḥīḥ