'Discern' in the Bible

Then thine handmaid said, The word of my lord the king shall now be comfortable: for as an angel of God, so is my lord the king to discern good and bad: therefore the LORD thy God will be with thee.

I am this day fourscore years old: and can I discern between good and evil? can thy servant taste what I eat or what I drink? can I hear any more the voice of singing men and singing women? wherefore then should thy servant be yet a burden unto my lord the king?