1 Samuel 1:11, 22, 27-28

She made a vow, saying, “O LORD of hosts, if You will indeed look on the affliction (suffering) of Your maidservant and remember, and not forget Your maidservant, but will give Your maidservant a son, then I will give him to the LORD all the days of his life; a razor shall never touch his head.”

But Hannah did not go up, for she said to her husband, “I will not go up until the child is weaned; and then I will bring him, so that he may appear before the LORD and remain there as long as he lives.”

For this child I prayed, and the LORD has granted me my request which I asked of Him. Therefore I have also dedicated him to the LORD; as long as he lives he is dedicated to the LORD.” And they worshiped the LORD there.