Hadithcore
Mishkat al-Masabih, 1527

Thauban reported God’s messenger as saying, “When a Muslim pays a sick visit to his brother Muslim he continues to gather the fruits of paradise till he returns.” Muslim transmitted it.

وَعَنْ ثَوْبَانَ قَالَ: قَالَ رَسُولُ اللَّهِ صَلَّى اللَّهُ عَلَيْهِ وَسَلَّمَ: «إِنَّ الْمُسْلِمَ إِذَا عَادَ أَخَاهُ الْمُسلم لم يزل فِي خُرْفَةِ الْجَنَّةِ حَتَّى يَرْجِعَ» . رَوَاهُ مُسْلِمٌ

References1 variant
In-Book Reference
Book 5, Hadith 5