Where does “мудрствовать” come from?

мудрствовать (Russian) comes from Russian му́дрство, from Russian му́дрый, from Old East Slavic мудръ, from Proto-Slavic mǫdrъ, from Proto-Indo-European modʰros, from Proto-Indo-European meh₂d- — to be wet, to become wet; to meet, approach,...

мудрствовать (Russian): to philosophize