What does 1 Samuel 1:11 mean?

She made a promise, saying, 'Lord of all, if you really see how miserable I am and remember me, and if you don’t forget me but give me a son, I’ll dedicate him to you for his whole life. He’ll never cut his hair as a sign he belongs to you.' 1 Samuel 1:11 - Modern Text Bible

(Hannah vows that if God gives her a son, she’ll give him back to God’s service, showing her deep faith and willingness to let go of what she wants most.)