The Messenger of Allah ﷺ said, "The example of a sick person when he recovers and regains health is like a hailstone falling from the sky in its purity and color."
حدثنا علي بن حجر قال أخبرنا الوليد بن محمد الموقري عن الزهري
قال رسول الله ﷺ إنما مثل المريض إذا برأ وصح كالبردة تقع من السماء في صفائها ولونها
No references are available.
[Daif] Ibn Adi recorded it in 7/2534 through Ali bin Hajar with this wording, and its chain is extremely daif. Ibn Jawzi included it in al-Mawdu'at, 3/200, 201, and quoted Ibn Hibban as saying, "This hadith is baseless, it is merely a statement of Zuhri, and no one attributed it to Zuhri as a raised report except Waqidi, and Waqidi, as noted in Taqrib and elsewhere..." The hadith has other chains as well, all extremely daif.