both - rather, “The things also which ye have learned ... these practice”; the things which besides recommending them in words, have been also recommended by my example, carry into practice.
heard - though ye have not yet sufficiently “received” them.
seen - though ye have not as yet sufficiently “learned” them [Bengel].
and - “and then,” as the necessary result (Phi 4:7). Not only “the peace of God,” but “the God of peace” Himself “shall be with you.”