Mark 13:12

Now the brother shall betray the brother to death
Signifying, that such should be the rage of men, particularly the Jews, against Christ and his Gospel, that those that were in the nearest relation, were of the same flesh and blood, children of the same parents, should betray and deliver up each other into the hands of the civil magistrate, in order to be put to death:

and the father the son; and children shall rise up against their
parents, and shall cause them to be put to death;
things unnatural and shocking; (See Gill on Matthew 10:21).