A man praised another man in front of the Prophet. The Prophet ﷺ said thrice, "Wailaka (Woe on you) ! You have cut the neck of your brother!" The Prophet ﷺ added, "If it is indispensable for anyone of you to praise a person, then he should say, "I think that such-and-such person (is so-and-so), and Allah is the one who will take his accounts (as he knows his reality) and none can sanctify anybody before Allah (and that only if he knows well about that person.)".
أَثْنَى رَجُلٌ عَلَى رَجُلٍ عِنْدَ النَّبِيِّ ﷺ فَقَالَ وَيْلَكَ قَطَعْتَ عُنُقَ أَخِيكَ ثَلاَثًا مَنْ كَانَ مِنْكُمْ مَادِحًا لاَ مَحَالَةَ فَلْيَقُلْ أَحْسِبُ فُلاَنًا وَاللَّهُ حَسِيبُهُ وَلاَ أُزَكِّي عَلَى اللَّهِ أَحَدًا إِنْ كَانَ يَعْلَمُ