A man was mentioned before the Prophet ﷺ and another man praised him greatly The Prophet ﷺ said, "May Allah's Mercy be on you ! You have cut the neck of your friend." The Prophet ﷺ repeated this sentence many times and said, "If it is indispensable for anyone of you to praise someone, then he should say, 'I think that he is so-and-so," if he really thinks that he is such. Allah is the One Who will take his accounts (as He knows his reality) and no-one can sanctify anybody before Allah." (Khalid said, "Woe to you," instead of "Allah's Mercy be on you.") (Using translation from Bukhārī 6061)
أَنَّ رَجُلًا ذُكِرَ عِنْدَ النَّبِيِّ ﷺ فَأَثْنَى عَلَيْهِ رَجُلٌ خَيْرًا فَقَالَ رَسُولُ اللهِ ﷺ وَيْحَكَ قَطَعْتَ عُنُقَ صَاحِبِكَ يَقُولُهُ مِرَارًا إِنْ كَانَ أَحَدُكُمْ مَادِحًا أَخَاهُ لَا مَحَالَةَ فَلْيَقُلْ أَحْسِبُ كَذَا وَكَذَا إِنْ كَانَ يَرَى أَنَّهُ كَذَاكَ وَحَسِيبُهُ اللهُ وَلَا يُزَكِّ أَحَدٌ عَلَى اللهِ