Mishkat al-Masabih
Mishkat al-Masabih 1587
Arabic hadith text
وَعَنْ أَنَسٍ قَالَ: كَانَ النَّبِيُّ صَلَّى اللَّهُ عَلَيْهِ وَسَلَّمَ لَا يَعُودُ مَرِيضًا إِلَّا بَعْدَ ثَلَاثٍ. رَوَاهُ ابْنُ مَاجَهْ وَالْبَيْهَقِيُّ فِي شُعَبِ الْإِيمَانِ
Translation
Anas said: The Prophet would not visit a sick person until after three days.
Ibn Majah and al-Bayhaqi transmitted it in Shuab al-Iman.