The opening word of today's text is translated in the ESV as that old English word, "Thus..." - "Thus is was necessary..."(23). "Thus" is a summation word. It means our writer is forming a conclusion based on something said earlier. And the conclusion he's about to reach is based on his description just two verses earlier of the purification of all those places and instruments of sacrifice in the Holy Place and the Holy of Holies under the old covenant:
Hebrews 9:21-22 - "And in the same way he sprinkled with the blood both the tent and all the vessels used in worship. Indeed, under the law almost everything is purified with blood, and without the shedding of blood there is no forgiveness of sins.
What our writer doesn't bother explaining in those two verses is why these inanimate objects needed purifying. Is he really asking us to believe a tent or a pan or a knife or a lamp could be wicked or sinful in itself? And the answer, I think, is no. Our writer is neither naive nor suspicious. Those material things in themselves are morally neutral and unresponsive. But they were all used by sinful people. They were used by idolaters and adulterers and Sabbath breakers and thieves and liars and ignorers of God. At the very best of times those instruments and rooms were all used by covenant breakers. They were used by nothing but covenant breakers.