Sayyiduna Sahl bin Sa'd al-Sa'idi (may Allah be pleased with him) reports this saying of the Prophet (peace and blessings be upon him): "Among the people of faith, the believer is like the head in relation to the body. The believer feels pain for the people of faith just as the body feels pain because of the pain in the head."
Ahmad recorded it, and al-Tabarani in al-Mu'jam al-Kabir and al-Mu'jam al-Awsat; the narrators of Ahmad are the narrators of the Sahih.
Hadith Takhrij«اخرجه الطبراني فى المعجم الكبير (5743) أخرجه الطبراني فى المعجم الصغير (340/5) ، أخرجه مسند أحمد برقم: 22370، وأخرجه المعجم الكبير للطبراني برقم: 5743»