The Messenger of Allah ﷺ said, "Whoever performs a deed to be heard of by people, Allah will make every one of His creatures who hears of him belittle and despise him."
عن رسول الله ﷺ قال: من سمع الناس بعمله سمع الله به سامع خلقه، وصغره وحقره.
Tabarani related it in al-Kabir (14414), and Abu Naeem in al-Hilya (4/123-124), both by way of Qasim bin Zakariya, who said, "Abdul-Rahim bin Muhammad Sukkari gave me a book, and I copied from it, Abbad bin Awwam narrated to us, Abu Aban bin Taghlib narrated to us, from Amr bin Mura, from Khaythama, from Abdullah bin Amr," and he mentioned it. Its isnad is sahih.Ahmad related it (6509) by another route, from Amr bin Mura, "I heard a man in the house of Abu Ubayda say that he heard Abdullah bin Amr narrating to Ibn Umar that the Messenger of Allah ﷺ said," and he mentioned the hadith in the same way. He said, "So Abdullah's eyes shed tears." The unnamed man is Khaythama bin Abdul-Rahman, as mentioned above, and he is trustworthy. It also appears in Ahmad (7085) with his kunya (Abu Yazid).On this subject there is also what was related from Abu Saeed Khudri, who said, the Messenger of Allah ﷺ said, "Whoever shows off, Allah will expose him for it, and whoever makes a show of listening, Allah will expose him for it, and whoever does not show mercy to people, Allah will not show him mercy." This is daif. Tirmidhi (2381), Ibn Majah (4206), and Ahmad (11357) all related it through various routes from Atiya Awfi, from Abu Saeed Khudri, who mentioned it. The wording given is Tirmidhi's, and Ahmad and Ibn Majah did not mention the part "whoever does not show mercy..." Atiya Awfi is Ibn Saad Kufi, and he is daif.