Silsilat al-Ahadith al-Sahihah

It is narrated from Sayyiduna Nu’man bin Bashir (may Allah be pleased with him) that the Messenger of Allah (peace and blessings be upon him) said: “In mutual love, mercy, and compassion for one another, the example of the believers is like that of a single body: when one limb suffers, the whole body responds with wakefulness and fever.”