The old testament is composed of endless laws and regulations for the people of Israel, which were extremely difficult to carry. This is why the apostle Paul says in Romans 8:2-3
2 For the law of the Spirit of life in Christ Jesus hath made me free from the law of sin and death.
3 For what the law could not do, in that it was weak through the flesh, God sending his own Son in the likeness of sinful flesh, and for sin, condemned sin in the flesh:
When we read the Law of Moses, we notice many laws that were difficult to keep or fulfill at face value and even think that it would be practically impossible to carry. Consider this, there were hundreds of laws, which that generation was very difficult to keep. And this is why in advance He had prepared a much better covenant. A covenant that says:
But this shall be the covenant that I will make with the house of Israel; After those days, saith the Lord, I will put my law in their inward parts, and write it in their hearts; and will be their God, and they shall be my people.