1 Samuel 1:9-11
1:9 On one occasion in Shiloh, after they had finished eating and drinking, Hannah got up. (Now at the time Eli the priest was sitting in his chair by the doorpost of the Lord’s temple.)
1:10 She was very upset as she prayed to the Lord, and she was weeping uncontrollably.
1:11 She made a vow saying, “O Lord of hosts, if you will look with compassion on the suffering of your female servant, remembering me and not forgetting your servant, and give a male child to your servant, then I will dedicate him to the Lord all the days of his life. His hair will never be cut.”