Zirr bin Hubaysh (may Allah have mercy on him) narrates: We came to Sayyiduna Safwan bin Assal (may Allah be pleased with him), and he asked: "Have you come to visit?" We said: "Yes." He said: The Messenger of Allah (peace and blessings be upon him) said: "Whoever visits his believing brother keeps walking in the gardens of Paradise until he returns, and whoever visits his believing brother when he is sick keeps walking in the gardens of Paradise until he returns."
Hadith Referenceالمعجم الكبير للطبراني / باب الصاد / 7358