Matthew 1:19

Greek ὤν, καὶ μὴ θέλων αὐτὴν. he who is and not he who desires. A "just one" (δίκαιος) is an adjective in the nominative and "he who is" (θέλων) is a masculine participle verb.  μὴ θέλων "not he who desires" is also a negated masculine participle verb. Participle verbs are not inconsequential.

Will vs. Desire

1. βούλομαι (boulomai) to will:

   • This verb often conveys a more deliberate or intentional desire. It can imply a desire that is reasoned or planned.
   • "βούλομαι" is frequently used in contexts involving decision-making, choice, or intentionality.
   • It can also convey a wish or desire that is considered more seriously or with greater consideration.
   • Example: "Βούλεσαι τοῦτο ποιήσαι;" (Boulesai touto poiēsai?) - "Do you wish/intend to do this?"

2. θέλω (thélo) to desire:

   • "θέλω" generally denotes a more immediate or spontaneous desire. It often implies a want or wish that arises more from impulse or inclination.
   • This verb is used in a wide range of contexts and can express desires ranging from simple preferences to strong wishes.
   • "As respects the distinction between βούλομαι and θέλω, the former seems to designate the will which follows deliberation, the latter the will which proceeds from inclination. This appears not only from Matthew 1:19, but also from the fact that the Sept. express the idea of pleasure, delight, by the verb θέλειν" - Thayers Greek Lexicon (Thayer, Joseph Henry. "STRONGS NT 2309: θέλω." Thayer's Greek Lexicon.)

not he who desires to make a show of herself. The following infinitive "to make a show of, example of" is a compound word not found in Greek writings, and therefore a special NT word derived from the noun "δεῖγμα" (deígma), meaning "example" or "demonstration," and the verb δεικνύω (deiknúo), meaning "to show" or "to demonstrate." So, δειγματίσαι refers to the act of demonstrating or proving a thing/person publically.