Hebrews 10:4

For it is not possible - Common sense must have taught them that shedding the blood of bulls and goats could never satisfy Divine justice, nor take away guilt from the conscience; and God intended that they should understand the matter so: and this the following quotation from the Psalmist sufficiently proves.

For it is not possible that the blood of bulls and of goats should take away sins - The reference here is to the sacrifices which were made on the great day of the atonement, for on that day the blood of bulls and of goats alone was offered; see the notes on Hebrews 9:7. Paul here means to say, doubtless, that it was not possible that the blood of these animals should make a complete expiation so as to purify the conscience, and so as to save the sinner from deserved wrath. According to the divine arrangement, expiation was made by those sacrifices for offences of various kinds against the ritual law of Moses, and pardon for such offences was thus obtained. But the meaning here is, that there was no efficacy in the blood of a mere animal to wash away a "moral" offence. It could not repair the Law; it could not do anything to maintain the justice of God; it had no efficacy to make the heart pure. The mere shedding of the blood of an animal never could make the soul pure. This the apostle states as a truth which must be admitted at once as indisputable, and yet it is probable that many of the Jews had imbibed the opinion that there was such efficacy in blood shed according to the divine direction, as to remove all stains of guilt from the soul; see the notes, Hebrews 9:9-10.

10:4 It is impossible the blood of goats should take away sins - Either the guilt or the power of them.