'Discern' in the Bible

Then your handmaid said, 'Please let the word of my lord the king bring rest; for as an angel of God, so is my lord the king to discern good and bad. May Yahweh, your God, be with you.'"

I am this day eighty years old. Can I discern between good and bad? Can your servant taste what I eat or what I drink? Can I hear any more the voice of singing men and singing women? Why then should your servant be yet a burden to my lord the king?