Jesus saith unto them, Have ye understood all these things? They say unto him, Yea, Lord. Then said he unto them, Therefore every scribe which is instructed unto the kingdom of heaven is like unto a man that is an householder, which bringeth forth out of his treasure things new and old.

Matthew 13:51-52

The duties of a scribe included many important jobs but the most important was to faithfully copy the scriptures for succeeding generations. They could not photocopy or scan the documents. They had to rigorously copy ever single mark on the page to ensure that the word of God was preserved. God committed this job to the Jews (Romans 3:2) because He promised He would preserve His word (Psalm 12:6-7).

The scribes had one job, but they didn’t do it faithfully.

Yes, they did continue to copy the true word of God but they also began copying and promoting the commentaries, philosophies and opinions of the rabbis for several generations. Jesus points this out in the Sermon on the Mount. Several times He says these words in some form, “Ye have heard that it hath been said by them of old time.” Jesus is referring to these sayings of the old teachers that had taken over most the subject matter being taught. By the time of the 1st century, the writings of men were placed on the same level of importance as the word of God. It is no wonder they didn’t recognize the Christ!!!

Later, Jesus would clearly state that this had led many away from the truth:

But in vain they do worship me, teaching for doctrines the commandments of men.

Matthew 15:9

The Apostle Paul warned TItus to avoid these teachings:

Not giving heed to Jewish fables, and commandments of men, that turn from the truth.

Titus 1:14

One of the things this parable teaches us is that we are to only teach what God has taught us to teach.  While not directly pointing out the errors of the practices of the scribes, Jesus teaches the proper duty of any who have been blessed to understand and carry forward that understanding of God’s word.

And the things that thou hast heard of me among many witnesses, the same commit thou to faithful men, who shall be able to teach others also.

2nd Timothy 2:2