The Prophet (ﷺ) said: "Whoever amongst you has to praise his brother should say:
أَحْسِبُ فُلَانًا وَاللَّهُ حَسِيبُهُ وَلَا أُزَكِّي عَلَى اللَّهِ أَحَدًا أَحْسِبُهُ كَذَا وَكَذَا
Pronunciation
Ahsibu fulaanan wAllaahu haseebuhu wa laa 'uzakkee 'alAllaahi 'ahadan ahsibuhu kadha wa kadha
Meaning
I think that he is so and so, and Allah knows exactly the truth, and I do not confirm anybody's good conduct before Allah, but I think him so and so. It is to be said when you must ensure you have knowledge that the certain characteristic is present in that person.
Source: Bukhari: 2662
Read the hadith
حَدَّثَنَا مُحَمَّدُ بْنُ سَلَامٍ أَخْبَرَنَا عَبْدُ الْوَهَّابِ حَدَّثَنَا خَالِدٌ الْحَذَّاءُ عَنْ عَبْدِ الرَّحْمَنِ بْنِ أَبِي بَكْرَةَ عَنْ أَبِيهِ قَالَ أَثْنَى رَجُلٌ عَلَى رَجُلٍ عِنْدَ النَّبِيِّ صَلَّى اللَّهُ عَلَيْهِ وَسَلَّمَ فَقَالَ وَيْلَكَ قَطَعْتَ عُنُقَ صَاحِبِكَ قَطَعْتَ عُنُقَ صَاحِبِكَ مِرَارًا ثُمَّ قَالَ مَنْ كَانَ مِنْكُمْ مَادِحًا أَخَاهُ لَا مَحَالَةَ فَلْيَقُلْ أَحْسِبُ فُلَانًا وَاللَّهُ حَسِيبُهُ وَلَا أُزَكِّي عَلَى اللَّهِ أَحَدًا أَحْسِبُهُ كَذَا وَكَذَا إِنْ كَانَ يَعْلَمُ ذَلِكَ مِنْهُ
Narrated Abu Bakra: A man praised another man in front of the Prophet (ﷺ) . The Prophet (ﷺ) said to him, "Woe to you, you have cut off your companion's neck, you have cut off your companion's neck," repeating it several times and then added, "Whoever amongst you has to praise his brother should say, 'I think that he is so and so, and Allah knows exactly the truth, and I do not confirm anybody's good conduct before Allah, but I think him so and so,' if he really knows what he says about him." [Bukhari: 2662]
Duas from IslamicAPI's Masnun Dua dataset (based on the Quran, hadith, Hisnul Muslim and Rahe Belayat). See the dataset