Just like in the Old Testament, in the rabbinic writings there is a twofold emphasis on the Day of Atonement, namely accessing to God and cleansing from God. And the high priest was the only person, who was permitted to enter the Holy of Holies only once in the whole year (cf. Hebrews 9:7). On this regard, in his book The Atonement, Leon Morris writes:
The writer to the Hebrews bears this in mind. He points out that Christ entered the heavenly Holy Place not ‘by means of the blood of goats and calves; but he entered the Most Holy Place once for all by his own blood, having obtained eternal redemption’ (Heb. 9:12). The contrast between the blood of Christ and the blood of animals is important, for ‘it is impossible for the blood of bulls and goats to take away sins’ (Heb. 10:4). Just as it was impossible for animal blood to take away sin, so it was impossible for it to secure access. Christ’s blood is different. It really opens up the way into the presence of God (p. 83).