The Book of the Believer · Hadith 154 (#Ḥadīth #9)
Chapter 6 | Visiting a Believer Socially and When He is Ill
154 - وعن أبي عبد الله عليه السلام قال: قال رسول الله صلى الله عليه و آله وسلم: أيما مسلم عاد مريضا عن المؤمنين خاض رمال الرحمة، فإذا جلس إليه غمرته الرحمة، فإذا رجع إلى شيعه سبعون ألف ملك حتى يدخل إلى منزله، كلهم يقولون: ألا طبت وطابت لك الجنة.
154. It has been reported that Abu 'Abd Allah said: the Messenger of Allah said: Any Muslim who visits a sick believer will be absorbed in mercy. When he sits with him (the sick believer), mercy will submerge him; and when he returns, he will be accompanied by seventy thousand angels until he enters his house, every one of them saying, 'Rejoice and enjoy Paradise.'
Gradings are classical jarḥ-wa-taʿdīl, name-matched to a rijāl index (not individually re-verified).