6 Suffer not thy mouth to cause thy flesh to sin; neither say thou before the angel, that it was an error: wherefore should God be angry at thy voice, and destroy the work of thine hands?
6 Do not let your mouth lead you into sin. And do not protest to the temple messenger, "My vow was a mistake." Why should God be angry at what you say and destroy the work of your hands?
6 Let not your mouth lead you
6 Don't let your mouth make a total sinner of you. When called to account, you won't get by with "Sorry, I didn't mean it." Why risk provoking God to angry retaliation?
6 Do not let your mouth cause your flesh to sin, nor say before the messenger of God that it was an error. Why should God be angry at your excuse and destroy the work of your hands?
6 Don't let your mouth make you sin. And don't defend yourself by telling the Temple messenger that the promise you made was a mistake. That would make God angry, and he might wipe out everything you have achieved.
Matthew Henry's Commentary on Ecclesiastes 5:6
Commentary on Ecclesiastes 5:4-8
(Read Ecclesiastes 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.