Gr. rhēma, “utterance,” “saying,” “statement.” Compare the use of the term in Rom. 10:8, 17; 2 Cor. 13:1; Heb. 1:3. Many commentators see a reference here to the formula used in connection with the rite of baptism (see Matt. 28:19). Others see a reference to the utterance of faith by the new convert (Rom. 10:8-10). Still others apply rhēma to the gospel or to the word of faith preached prior to baptism.

Or, “in,” meaning “by means of.”

 Gr. loutron, “bath,” “bathing place,” or “bathing.” The word occurs elsewhere in the NT only in Titus 3:5, where it appears in the expression “washing of regeneration.” Since the context is that of marriage, there is probably an allusion to the ancient custom of the purifying bath of the bride before marriage. Or the reference may be to baptism. In either case, the idea is that Christ has purified the church. Christ gave Himself for the church that she might become a pure church, and so abide with Him forever.

 Christ took away the filthy garments and gave, instead, the robe of His perfect righteousness (see on Matt. 22:11).