5:12 {7} But above all things, my brethren, swear not, neither by heaven, neither by the earth, neither by any other oath: but let {f} your yea be yea; and [your] nay, nay; lest ye fall into condemnation.
(7) Because even the best men sometimes through impatience slip and speak oaths sometimes lesser, sometimes greater, the apostle warns us to detest such wickedness, and to accustom our tongues to simple and true talk.
5:12 Above all things, my brethren, swear not. This verse is an appropriation of the words of Christ (Mt 5:33-37). See notes there. Swearing is a besetting sin of the East unto this day.
5:12 Swear not - However provoked. The Jews were notoriously guilty of common swearing, though not so much by God himself as by some of his creatures. The apostle here particularly forbids these oaths, as well as all swearing in common conversation. It is very observable, how solemnly the apostle introduces this command: above all things, swear not - As if he had said, Whatever you forget, do not forget this. This abundantly demonstrates the horrible iniquity of the crime. But he does not forbid the taking a solemn oath before a magistrate. Let your yea be yea; and your nay, nay - Use no higher asseverations in common discourse; and let your word stand firm. Whatever ye say, take care to make it good.
5:12-18 The sin of swearing is condemned; but how many make light of common profane swearing! Such swearing expressly throws contempt upon God's name and authority. This sin brings neither gain, nor pleasure, nor reputation, but is showing enmity to God without occasion and without advantage It shows a man to be an enemy to God, however he pretends to call himself by his name, or sometimes joins in acts of worship. But the Lord will not hold him guiltless that taketh his name in vain. In a day of affliction nothing is more seasonable than prayer. The spirit is then most humble, and the heart is broken and tender. It is necessary to exercise faith and hope under afflictions; and prayer is the appointed means for obtaining and increasing these graces. Observe, that the saving of the sick is not ascribed to the anointing with oil, but to prayer. In a time of sickness it is not cold and formal prayer that is effectual, but the prayer of faith. The great thing we should beg of God for ourselves and others in the time of sickness is, the pardon of sin. Let nothing be done to encourage any to delay, under the mistaken fancy that a confession, a prayer, a minister's absolution and exhortation, or the sacrament, will set all right at last, where the duties of a godly life have been disregarded. To acknowledge our faults to each other, will tend greatly to peace and brotherly love. And when a righteous person, a true believer, justified in Christ, and by his grace walking before God in holy obedience, presents an effectual fervent prayer, wrought in his heart by the power of the Holy Spirit, raising holy affections and believing expectations and so leading earnestly to plead the promises of God at his mercy-seat, it avails much. The power of prayer is proved from the history of Elijah. In prayer we must not look to the merit of man, but to the grace of God. It is not enough to say a prayer, but we must pray in prayer. Thoughts must be fixed, desires must be firm and ardent, and graces exercised. This instance of the power of prayer, encourages every Christian to be earnest in prayer. God never says to any of the seed of Jacob, Seek my face in vain. Where there may not be so much of miracle in God's answering our prayers, yet there may be as much of grace.