Jesus knew that God had inspired King David to totally change the Law. In Psalm 49  (quoted here from "Bible Wisdom: PSALMS of Praise and Power"), David wrote:
"Hear Me, My people!
I will speak to you, Israel,
and I will testify against you!
I am the Lord God, your God!
I reprimand you on account of your 'sacrifices'
and the 'burnt offerings' you continually bring Me.
They are not acceptable to Me!
I refuse to accept bulls from your farms
and goats from your flocks,
because every animal is already Mine:
All the wild beasts of the thickets are Mine,
all the oxen on the mountains,
and all the cattle on a thousand hills.
Do I eat the flesh of bulls
or drink the blood of goats?
No! So why do you sacrifice
these animals to Me?
Rather, you should sacrifice to your God
the sacrifice of praise!
And you should pay your vows to the Most High,
not to the priests nor to the temple!
You should call upon Me (and Me alone)
whenever you’re in trouble,
and I will deliver you – and you will praise Me!
Yes, it is the sacrifice of praise that will honor and glorify Me;
and that is the way in which I will show you My salvation."
This Psalm is another that the Temple priests interfered with by inserting a "do not" in front of "reprimand" and deleting the "not" in front of "acceptable". Making these changes has the effect of making God speak absolute rubbish. In one sentence He says he will accept sacrifices and in the very next sentence He says He will refuse them! Though no doubt the priests would interpret His words as applying only to the bulls and the goats! And of course they also deleted the "not to the priests nor the temple" line. No wonder Jesus had such a poor opinion of the priests and their hangers-on!