In Contrast Are Those Whose Offerings and Sacrifices Are Merely Formal And Debased And Not From The Heart (Isaiah 66:3-5).
“He who kills an ox is as he who slays a man,
He who sacrifices a lamb as he who breaks a dogs neck,
He who offers an oblation as he who offers swine's blood,
He who burns frankincense as he who blesses an idol,
Yes, they have chosen their own ways,
And their inner being delights in their abomination.”
This is where we began in Isaiah 1:10-17. There are those who are very religious, but whose religion is formal with no heart in it. They are not humble and contrite, but proud of their religious activity, while thinking that once they have indulged in it they can then indulge in whatever they want. It is but a religious exercise. They honour Him with their lips, draw near to Him with their mouths, but their hearts are far from Him.
Thus when they slay an ox God sees it simply as murder, when they sacrifice a lamb it means nothing more to Him than the breaking of a dog's neck (compare Isaiah 1:11). This was the lowest possible event, for even the price of a dog could not be brought to Yahweh (Deuteronomy 23:18), stressing the total unacceptability of such an offering as this, which He did not even regard as an offering but as an insult. A dog, like an ass (Exodus 13:13), would be killed by breaking its neck because it could not be offered as a sacrifice.
This is followed by likening their actions to two further abominations, swine's blood and idolatry. When they offer an oblation it is as if they were offering swine's blood, an abomination to God. When they burn frankincense it is as if they offered it to other gods, it is an abomination to Him (compare Isaiah 1:13). So they are guilty of murder, of bringing a dog into the temple and breaking its neck before Yahweh, of offering swine's blood and of blessing an idol.
This indicates that their worship is not only formal but is abominable, because it is carried on without genuine worship amid the paraphernalia used for the worship of the hosts of heaven and other false gods (Ezekiel 8:5-18 brings this out equally vividly). Perhaps today we should consider the paraphernalia that we introduce into worship services, and ask ourselves whether it is really assisting worship, or whether it is actually taking our minds way from God.
That is why God wants nothing of their ritual because it is all formal and syncretistic, and not from the heart. It is carried out as a matter of course, and to try to ‘influence' God's favour, and not because it comes from deeply penitent hearts which seek fellowship with Him.
This is demonstrated by the fact that while they do it they go in their own ways (see Isaiah 53:6) and their very soul delights in this mockery which pretends to be worship. This could be seen as quite acceptable to false gods who have no interest in morality, indeed in anything, but not to the living God. Yet even though it is an abomination to God they themselves are very satisfied with it, and with themselves, demonstrating what they really are and that they really do deserve judgment.
“I also will choose the harsh way they are treated (the due reward for their deeds),
And will bring their fears on them,
Because when I called, none answered,
When I spoke they did not hear.
But they did what was evil in my eyes,
And chose that in which I did not delight.
So because they have cut Him off in their hearts God will select their punishment and bring on them what they have feared. Their ritual was designed to somehow, by manipulation, make Yahweh act to deal with their fears, but He will instead bring what they feared on them. He will respond in accordance with the lack of genuineness in their worship.
Note the semi-parallel in Isaiah 65:12 which ends in the same way. But there it is ‘I will destine you to the sword' rather than ‘I will choose the harsh way they are treated', for there they had been following Destiny, and therefore their destiny is described, while here they are insulting Yahweh by formalism and He therefore describes His personal punishment.
And the reason is because they have not listened to His call or His words through Isaiah and through other prophets. They have not listened and they have not responded. Their hearts are too hardened. Rather they have continued in sinful ways, and have chosen to do things which Yahweh did not enjoy and which gave Him no delight (compare Isaiah 65:12 where it is related to fortune telling and idolatry).