Muslim exegesis of this verse points out perhaps the pinnacle of proof texted nonsense, peddled by their Greek sophist styled entertainers, like Ahmed Deedat.
Mat 12:40 For as Jonas was three days and three nights in the whale's belly; so shall the Son of man be three days and three nights in the heart of the earth.
The verse means what it says. It is about each of their stays of 3 days and 3 nights.
Muslims actually remove this from context, and then add the add a fantastic presumption that is has something to do with being alive or dead, which, of course, it obviously doesn't or it would be inconsistent with the WHOLE SUBJECT of the New Testament which is the new covenant we were given through Jesus Christ and all of the Old Testament prophecy regarding the promise of that new covenant through Jesus Christ. The subject is simply the 3 days and nights, just as it says.
Here is another example where Jesus prophesies His death and resurrection in 3 days:
John 2:19 Jesus answered and said unto them, Destroy this temple, and in three days I will raise it up. 20 Then said the Jews, Forty and six years was this temple in building, and wilt thou rear it up in three days? 21 But he spake of the temple of his body. 22 When therefore he was risen from the dead, his disciples remembered that he had said this unto them; and they believed the scripture, and the word which Jesus had said.
Though Muslims shepherd a lot of false presumption, few make more clear than this, that these poor folks suffer under the strong delusion of not only their false prophet Mohammed, but the battery of their Greek sophist styled liars for Mohammed like Ahmed Deedat.
Their sense of right and wrong has been inverted by that spirit of antichrist. They prefer a lie to the truth.
2Thes 2:8 And then shall that Wicked be revealed, whom the Lord shall consume with the spirit of his mouth, and shall destroy with the brightness of his coming: 9 [EVEN HIM],WHOSE COMING IS AFTER THE WORKING OF SATAN with all power and signs and lying wonders, 10 And with all deceivableness of unrighteousness in them that perish; because THEY RECEIVED NOT THE LOVE OF THE TRUTH, that they might be saved. 11 And for this cause God shall send them strong delusion, THAT THEY SHOULD BELIEVE A LIE: 12 That they all might be damned who believed not the truth, but had pleasure in unrighteousness.