I say this as a concession, not as a command.

1 Corinthians 7:10
To the married I give this command (not I, but the Lord): A wife must not separate from her husband.

1 Corinthians 7:12
To the rest I say this (I, not the Lord): If a brother has an unbelieving wife and she is willing to live with him, he must not divorce her.

1 Corinthians 7:25
Now about virgins, I have no command from the Lord, but I give a judgment as one who by the Lord's mercy is trustworthy.

1 Corinthians 7:40
In my judgment, however, she is happier if she remains as she is. And I think that I too have the Spirit of God.

2 Corinthians 8:8
I am not making a demand, but I am testing the sincerity of your love in comparison to the earnestness of others.

But I speak this by permission, and not of commandment.