لَقِيتُ عَالِمًا.
I met a scholar.
The indefinite noun does not inherently mean that the scholar is insignificant, exceptional, unknown in every respect, or quantitatively small. Effects such as magnification, belittlement, and minimization require contextual evidence; tanwīn alone cannot establish them.
لَقِيتُ عَالِمًا يَنْتَفِعُ النَّاسُ بِعِلْمِهِ.
I met a scholar whose knowledge benefits people.
The modifying relative clause highlights the practical value of the person’s learning. Its contribution should be distinguished from any rhetorical purpose assigned to the indefiniteness of the noun.