Numbers 30:1
And Moses spake unto the heads of the tribes concerning the children of Israel, saying, This is the thing which the LORD hath commanded. And Moses spake unto the heads of the tribes concerning the children of Israel, saying, This is the thing which the LORD hath commanded.
This verse introduces the Lord's command concerning vows made by Israel, spoken through Moses to the heads of the tribes concerning the children of Israel. The command treats a vow made to the Lord as sacred and binding, requiring that it be kept. The one who has vowed must not break his word but must do all that was promised and fulfill what was spoken. That obligation includes pledges to give for God's cause, which must not be dismissed as a mistake or casually withdrawn.