1 Samuel 1:11-13

11And she vowed a vow, and said, O LORD of hosts, if thou wilt indeed look on the affliction of thy handmaid, and remember me, and not forget thy handmaid, but wilt give to thy handmaid a son, then I will give him to the LORD all the days of his life, and there shall no razor come upon his head.1 12And it came to pass, as she continued praying before the LORD, that Eli observed her mouth.2 13Now Hannah, spoke in her heart; only her lips moved, but her voice was not heard: therefore Eli thought she was drunk.