Matthew Henry's Concise Commentary

5:4-8 When a person made engagements rashly, he suffered his mouth to cause his flesh to sin. The case supposes a man coming to the priest, and pretending that his vow was made rashly, and that it would be wrong to fulfil it. Such mockery of God would bring the Divine displeasure, which might blast what was thus unduly kept. We are to keep down the fear of man. Set God before thee; then, if thou seest the oppression of the poor, thou wilt not find fault with Divine Providence; nor think the worse of the institution of magistracy, when thou seest the ends of it thus perverted; nor of religion, when thou seest it will not secure men from suffering wrong. But though oppressors may be secure, God will reckon for all.