“But he said unto them, All men cannot receive this saying, save they to whom it is given.”
King James Version (KJV)
19:11 But he said to them - This is not universally true; it does not hold, with regard to all men, but with regard to those only to whom is given this excellent gift of God. Now this is given to three sorts of persons to some by natural constitution, without their choice: to others by violence, against their choice; and to others by grace with their choice: who steadily withstand their natural inclinations, that they may wait upon God without distraction.
Mt 19:11 To whom it is given. Only those can receive and live up to this rule who are enlightened by Christianity. The less Christianity, the lower the ideal of marriage. This is the rule everywhere.