He (sal-Allaahu 'alayhe wa sallam) said: "If anyone of you is impelled to praise his brother, then he should say:

أَحْسِبُ فُلَانًا وَاللّٰهُ حَسِيْبُهُ وَلَا أُزَكِّيْ عَلَى اللّٰهِ أَحَدًا أَحْسِبُهُ كَذَا وَكَذَا

I deem so-and-so to be...and Allaah is his reckoner...and I don't praise anyone, putting it [i.e., my praising] forward, in front of Allaah's commendation, however I assume him to be such and such" - if he knows that of him.