Hey TBH, how do you know how to pronunce the Hebrew letters, what they are, how to pronounce Hebrew words, etc.?If you read your post...you will notice that you are adding words to what Isaiah wrote, changing his meaning to conform to your misunderstanding. That's his point.
It does not say "...that offering sacrifices in the temple is a 'rule taught by men.'" Your conclusion is not close. The law given in the Torah is the Law. What rabbinical Judaism has added, the "oral Torah" is added...and taught and enforced through the ages by men rather than God, being vindicated by their antiquity alone.
And you have illustrated it perfectly.