'Burden' in the Bible

When he cut the hair of his head (for at the end of each year he cut it, because its weight was heavy on him) he weighed the hair of his head at 200 shekels by the king’s weight.

David said to him, “If you go on with me, you will be a burden to me.

I am this day eighty years old. Can I [be useful to advise you to] discern between good and bad? Can your servant taste what I eat or drink? Can I still hear the voices of singing men and women? Why then should your servant be an added burden to my lord the king?