if he doesn't eat at mountain shrines, and doesn't look to the idols that have been erected in Israel's house, if he doesn't defile his neighbor's wife or approach a woman during her time of menstrual separation,
That is, suppose he doesn't eat at the mountain shrines, doesn't look to the idols of Israel's house, doesn't defile his neighbor's wife,
even though the father hasn't done any of these things. The son who eats at mountain shrines, defiles his neighbor's wife,
Slanderous men live among you, intent on shedding blood. They've eaten at the top of mountain shrines. They've crafted plans to do evil things among you.
"Why do your disciples disregard the tradition of the elders? They don't wash their hands when they eat."
They noticed that some of his disciples were eating with unclean hands, that is, without washing them.
(The Pharisees and indeed all the Jewish people don't eat unless they wash their hands properly, following the tradition of their elders.
They don't eat anything from the marketplace unless they dip it in water. They also observe many other traditions, such as the proper washing of washing cups, jars, brass pots, and dinner tables.)
So the Pharisees and the scribes asked Jesus, "Why don't your disciples live according to the tradition of the elders? Instead, they eat with unclean hands."