Philemon 1
17 If then you count me as a partner, receive him as you would me. 18 But if he has wronged you or owes anything, put that on my account. 19 I, Paul, am writing with my own hand. I will repay—not to mention to you that you owe me even your own self besides. 20 Yes, brother, let me have joy from you in the Lord; refresh my heart in the Lord.

From my commentary:
Not to mention to you that you owe me even your own self besides: While “accounts” were being studied, Paul mentioned one more thing. “Philemon, remember that I have a lot of credit on your account, because you owe me even your own self besides.” Paul could afford to pay Onesimus’ expenses because there was a sense in which Philemon owed Paul his salvation!

So Paul acted just like Jesus. He took Onesimus’ debts and placed them on his own account so that Onesimus’ account would be clean.”

Paul is standing and vouching for a slave, that according to law should be punished. Paul is asking for lenience. He is asking for mercy.
Jesus does this for us! He stands and covers us so we have mercy and grace and purity in front of His father.

This is the truest act of LOVE.
Study this, this is LOVE.