To set forth, expose, or explain in detail. Used in Acts of Aquila and Priscilla expounding the way of God more accurately to Apollos (18:26), of Paul explaining his case to Jewish leaders (28:23), and of Moses' parents 'exposing' the infant Moses (7:21).
Ektithēmi carries both an ancient sorrow (the exposure of infant Moses) and a glorious calling (the explanation of God's word). In Acts 18:26, Priscilla and Aquila take the eloquent Apollos aside and 'expound to him the way of God more accurately' — a model of theological formation: precise, careful, generous exposition. In Acts 28:23, Paul 'expounded' the kingdom of God from morning to evening. The word suggests systematic, comprehensive, ordered explanation — the labor of teaching the whole counsel of God.