פּירוש אויף ירמיהו 31:31

Behold days are coming... new covenant. Its newness is that it will be kept, and not broken like the covenant that b'nei Yisrael cut with God at Mount Sinai. Regarding this and it says, for the prophet [Yirmiyahu] prophesies about a 'new Torah' which will in the future come to be. This isn't like a new Torah which was given at Mount Sinai, since it says "not according to the covenant that I made with their ancestors" (Yirmiyahu 31:32). This is the new Torah, that their repentance/returning has renewed for them. And behold it says, the explanation - and how is it "not according to the covenant that I made with their ancestors"? That they "broke my covenant" (ibid.) - and they will not break this covenant, because I will put my Tora in their hearts, "and on their hearts I will write it" (Yirmiyahu 31:33), so that they will never forget it. And the whole matter is as explained when it goes on, that it won't be a newness of the covenant but rather its fulfilment/keeping (קיומה). And behold it says, Malachi sealed the prophets with the seal of his words: "Remember the Tora of Moshe my servant, which I commanded him in Ḥorev for all Yisra᾽el, both statutes and judgments." (Malachi 3:22) - that whole section will be in the future, just like it seals "Behold, I will send you Eliyya, the prophet" (Malachi 3:23) - behold, you see tha there will never be a new Torah, but for the one which was given at Mount Sinai, like it says "which I commanded him in Ḥorev" (Malachi 3:22)