Matthew 5:36

36. Swear by thy head ”It is very common among the Orientals,” says Mr. Paxton in his Illustrations, “to swear by the life or head of the king.” Joseph, improperly yielding to the fashion of the country, swore by the life of Pharaoh; and this oath is still used in various parts of the East. According to Mr. Hanway, the most sacred oath among the Persians is by the head of the king; and Thevenot asserts that to swear by the head of the king is, in Persia, more authentic and of greater credit than if they swore by all that is most sacred in heaven and upon the earth. The ordinary phrase, “I will give you my head if it is not so,” is a colloquial form of swearing of the same kind; it pledges the head or the life upon the certainty of the affirmation.

Thou canst not make one hair white or black Thy life, thy head, thy every hair are all God’s workmanship, and their preservation is his act. To swear, therefore, by life or head, is to swear by the act, power, and person of God. The presumption of the oath reaches the Divine Being.