Is the companion of a destroyer - i. e., he stands on the same footing as the open, lawless robber. Compare this with our Lord's teaching as to Corban Mark 7:10-13.

Whoso robbeth his father - The father's property is as much his own, in reference to the child, as that of the merest stronger. He who robs his parents is worse than a common robber; to the act of dishonesty and rapine he adds ingratitude, cruelty, and disobedience. Such a person is the compatriot of a destroyer; he may be considered as a murderer.

Whoso robbeth his father or his mother,.... As Micah did of eleven hundred shekels of silver, Judges 17:2;
and saith, it is no transgression; what is his father's or his mother's is his own, or as good as his own, it will come to him at their death; and if he wants it before, he thinks he ought to have it; and if they are not willing to give it him, it is with him no sin to rob them of it; and this he says within himself, to quiet his conscience when he has done it; or to others who may charge him with it: but, whatever such a man thinks, sins against parents are greater than against others; as parricide is a greater sin than any other kind of murder, so robbing of parents is greater than any other kind of theft; it is more aggravated, especially when parents are aged, and cannot work for themselves, but depend on what they have for their livelihood; whereas a young man can, and ought, and should rather give to his parents than rob them of what they have;
the same is the companion of a destroyer; of a murderer; either he has got into such company which have put him upon such wicked practices; or he will soon get into such a society, and, from a robber of his father and mother, become a robber on the highway, and a murderer; and he has wickedness enough to be a destroyer of the lives of his parents, as well as of their substance; and sometimes the one sin leads to the other.

Here is the wickedness of those who think it no sin to rob their parents, by wheedling them or threatening them, or by wasting what they have, and running into debt.

(Compare Matthew 15:4-6). Such, though heirs, are virtually thieves, to be ranked with highwaymen.

24 He who robbeth his father and mother, and saith:
It is no wrong, Is a companion of the destroyer.
The second line is related to Proverbs 18:9. Instead of dominus perditionis there found, there is here אישׁ משׁחית, vir perdens (perditor); the word thus denotes a man who destroys, not from revenge, but from lust, and for the sake of the life of men, and that which is valuable for men; thus the spoiler, the incendiary, etc. Instead of אח there, here we have חבר in the same sense. He who robs his parents, i.e., takes to himself what belongs to them, and regards his doing so as no particular sin,
(Note: Accentuate ואמר אין פשׁע without Makkeph, as in Codd. 1294 and old editions.)
because he will at last come to inherit it all (cf. Proverbs 20:21 with Proverbs 19:26), to to be likened to a man who allows himself in all offences against the life and property of his neighbour; for what the deed of such a son wants in external violence, it makes up in its wickedness, because it is a rude violation of the tenderest and holiest demands of duty.

The same - Is a thief and robber.