It has been brought to my attention that there exists some groups within christianity that use Isaiah Chapter 1 to demonstrate that: "God no longer desires sacrifices or that He cancelled the necessity of keeping Sabbaths."
I would like to put this claim within its Jewish Context, aside from Rashi whom the majority of christians do not understand the importance of his commentary nor accept it, that the Sabbath and such ARE indeed crucial practices of Judaism and CANNOT be abrogated.
So this idea stems from their interpretation of these verses in Isaiah 1:
11 “The multitude of your sacrifices— what are they to me?” says the Lord. “I have more than enough of burnt offerings, of rams and the fat of fattened animals; I have no pleasure in the blood of bulls and lambs and goats.
13 Stop bringing meaningless offerings! Your incense is detestable to me. New Moons, Sabbaths and convocations— I cannot bear your worthless assemblies.
14 Your New Moon feasts and your appointed festivals I hate with all my being. They have become a burden to me; I am weary of bearing them.
As seen from a reading from their translation (for emphasis) and without any proper Jewish Context, they have come to that conclusion stated above.
So what is Isaiah speaking about here? Is he truly stating that God has condemned these practices?
I would like sources that span beyond Rashi, and bonus points if one can stick to Tanakh alone.