Calvin's Commentaries, Vol. 31: Matthew, Mark and Luke, Part I, tr. by John King, [1847-50], at sacred-texts.com
MATTHEW 6:14-15; Mark 11:25-26
14. For if you shall forgive men their trespasses, your heavenly Father will also forgive you. 15. But if you shall not forgive men their trespasses, neither will you Father forgive your trespasses.
25. And when ye shall stand praying, forgive, if you have any thing against any one, that your Father also, who is in heaven, may forgive you your trespasses. 26. But if you shall not forgive, neither will your Father, who is in heaven, forgive you your trespasses.
Here Christ only explains the reason why that condition was added, Forgive us, as we forgive The reason is, that God will not be ready to hear us, unless we also show ourselves ready to grant forgiveness to those who have offended us. If we are not harder than iron, this exhortation ought to soften us, and render us disposed to forgive offenses. 445 Unless God pardon us every day many sins, we know that we are ruined in innumerable ways: and on no other condition does he admit us to pardon, but that we pardon our brethren whatever offenses they have committed against us. Those who refuse to forget the injuries which have been done to them, devote themselves willingly and deliberately to destruction, and knowingly prevent God from forgiving them. 446
“Pour nous rendre faciles a oublier les injures qu'on nous a faites.” — “To make us ready to forget the injuries which have been done to us.”
“Et de propos delibere veulent que Dieu procede contre eux en toute rigueur;” — “and deliberately resolve that God may proceed against them to the utmost rigor.”