Infinitive, derived from "Claes die moetselt..." mentioned in a quotation in WNT from a stanza in P. Adrianus Poirters S.J., »Het masker vande wereldt afgetrocken« [The mask of the world taken off], Antwerpen 1688, in which the spelling is actually moetʃelt [3rd person singular, present tense]; NB¹: Unfortunately, the reference to the source mentioned in WNT is inactive (yet) as a link [ws, Nov. 2021]; NB²: ➺ Moeselen.