What shall I say, O my son? What, O son of my womb? What, O son of my vows?
Most interpreters are of opinion that Lemuel is Solomon; the name signifies one that is for God, or devoted to God; and so it agrees well enough with that honourable name which, by divine appointment, was given to Solomon (Sa2 12:25), Jedediah - beloved of the Lord.
Commenting on Proverbs 31:1-9
What, my son?.... What shall I call thee? though thou art a king, can I address thee in more suitable language, or use a more endearing appellative than this, and what follows? permit me, thy mother, to speak unto thee as my son: and what shall I say to thee?
What, my son? and what, the son of my womb? and what, the son of my vows? (c) By this often repetition of one thing, she declares her motherly affection.