Genesis 14:23 (c) Abraham uses this figure to tell the king that he would have nothing whatever from him, whether it be the least thing, or the greatest. It is a lesson to us that we should depend entirely on the Lord for our prosperity, and not on the favors of this wicked world.
John 1:27 (c) John thus describes his own unworthiness, because the least service one could render would be to kneel at the feet of a monarch and tie his shoe laces. John felt that he was not worthy to do even this.