Sayyiduna Thawban (may Allah be pleased with him) narrates that the Messenger of Allah (peace and blessings be upon him) said: "The one who visits the sick is among the fruits of Paradise until he returns."
He did not mention Abu al-Ash'ath in its chain, and the narration of Yazid and Marwan is more correct.
Hadith Referenceالسنن الكبرى للبيهقي / كتاب الجنائز / 6582