Wa laa ‘uzakkee ‘alallaahi ‘ahadan. I cannot claim anyone to be pious before Allah. وَلاَ أُزَكِّي عَلَى اللَّهِ أَحْدًا Muslim 4/2296.
How a Muslim should praise another Muslim
If any of you praises his companion then let him say أَحْسِب – فُلاَنَا – واللهُ حَسٍيْبُهُ ‘Ahsibu (fulaanan) wallaahu haseebuhu. I consider (such and such a person), and Allah is his Assessor. Muslim 4/2296.