Schaff's Bible Dictionary
VOW, in the scriptural use, means a solemn religious promise or covenant by which one binds himself to do or suffer certain things, depending on God for power to accomplish them. The first instance of such a vow recorded in Scripture is that made by Jacob when on the flight to Padan-aram. Gen 28:20-22; Gen 31:13. As vows were voluntary engagements, not prescribed by the Mosaic Law, they were made with prayer and paid with thanksgiving. Num 6:2-21; Jud 11:30-31; Ps 61:5; Acts 18:18. See Nazarites.