'Vow' in the Bible

And she vowed a vow, and said, O LORD of hosts, if thou wilt indeed look on the affliction of thine handmaid, and remember me, and not forget thine handmaid, but wilt give unto thine handmaid a man child, then I will give him unto the LORD all the days of his life, and there shall no rasor come upon his head.

And the man Elkanah, and all his house, went up to offer unto the LORD the yearly sacrifice, and his vow.