“وَ” (wa)a joining word meaning “and.” It connects this word to what came before.Corpus grammarCONJ — prefixed conjunction wa (and).
“لِ” (li)This prefix expresses purpose, like “in order to.”Corpus grammarPRP — prefixed prp particle.
“يُمَحِّصَ” (yumaḥḥiṣa)means “And so that may purify” in this verse. It is a verb. an action or state word. Here it is imperfect verb, verb pattern two, third person — masculine — singular, a dependent form.Corpus grammarV — third person masculine singular subjunctive imperfect verb.