Seeing you have purified your souls in your obedience to the truth through the Spirit in sincere brotherly affection, love one another from the heart fervently:
We do not make much melody on strings that are loose or that are stretched out. Likewise, we shall not love one another just with the strings, but with the strings stretched out. Loose strings produce no melody or harmony whether on a harp or on a heart. We should love one another with the heart strings stretched out.