For as with a zeal beyond the others he had confessed the King of heaven, he is deservedly entrusted more than the others with the keys of the heavenly kingdom, that it might be clear to all, that without that confession and faith none ought to enter the kingdom of heaven. By the keys of the kingdom He means discernment [margin note: discretio] and power; power, by which he binds and looses; discernment, by which he separates the worthy from the unworthy.
It follows, “And whatsoever thou shalt bind;” that is, whomsoever thou shalt judge unworthy of forgiveness while he lives, shall be judged unworthy with God; and “whatsoever thou shalt loose,” that is, whomsoever thou shalt judge worthy to be forgiven while he lives, shall obtain forgiveness of his sins from God.
Reproduced in full. Translation: Oxford 1841 (Newman), public domain (Public domain).