How accurate is the phrase "he who praises himself is a liar," and does it have a basis in the Prophetic Sunnah? And is praise divided into praiseworthy and blameworthy?

The phrase "لا نعلم أصلاً لهذه العبارة" (we do not know any origin for this phrase) has no basis. However, it is established in Islamic law that self-praise and self-commendation are prohibited, based on the Almighty's saying: "So do not assert purity for yourselves. He is most knowing of who is righteous." [An-Najm: 32]. This is only permissible if there is a recognized benefit behind the commendation and the praise is truthful.