Numbers 30:10

And she made a vow and said, “O Yahweh of hosts, if You will indeed look on the affliction of Your maidservant and remember me and not forget Your maidservant, but will give Your maidservant a seed amongst men, then I will give him to Yahweh all the days of his life, and a razor shall never come on his head.”

And Elkanah her husband said to her, “Do what is good in your eyes. Remain until you have weaned him; only may Yahweh establish His word.” So the woman remained and nursed her son until she weaned him.