Colossians 3:19

Ye husbands, love your wives, and be not bitter against them (Ephesians 5:25-31; 1 Peter 3:7). "Love" is ἀγαπάω, the word which expresses the highest spiritual affection—"even as Christ loved the Church" (Ephesians 5:25).

Here, first and most of all, the "new commandment" of John 13:34 applies. St. Paul only uses the verb πικραίνω ("to make bitter") here, but he has the noun πικρία ("bitterness") in a wider application in Ephesians 4:31.

It denotes "exasperation," prompting to hasty severity. Bengel defines it as "odium amori mixtum"—hatred infused into love.