Hebrews 6:16

16. An oath Greek, the oath; that is, the (institution of the) oath. The oath is a divine institution, the colloquial abuse of which is forbidden by Christ as profanity. So far is this from abolishing the true oath, which is an end of all strife, the Lord’s purpose was to forbid its colloquial desecration in order to secure its solemn sanctity. So Philo says, “By an oath doubtful things are decided, infirm things are confirmed, and the untrusted receive trust.” The ancient proverb is, “The man is the surety of the oath, not the oath of the man.” So Philo says, “Men, when mistrusted, have recourse to the oath to gain credence for themselves; but God, when simply speaking, is worthy of belief, so that his word is no way different from an oath.” And a sublime passage in the Talmud (quoted by Delitzsch) says, “Moses spoke before the Holy One: (blessed be He:) Lord of the world, hadst thou sworn to them by heaven and earth, I should have thought that as heaven and earth pass away, so, also, thine oath would pass away; but thou hast sworn to them by Thy great Name. It is so, then, that as Thy great Name liveth and endureth forever, Thine oath endureth forever also.”