many of His disciples murmured agree
Jesus knew in Himself that His disciples murmured agree
He said some of them did not believe. He said many did not believe.
Many of them went back (protested against His teaching when it was hard) and walked with Him no more.
Here is where you disagree with the texts illustrating why context is so important.
64But there are some of you who do not believe. For Jesus knew from the beginning who they were who did not believe, and who it was that would betray Him. 65And He was saying, For this reason I have said to you, that no one can come to Me unless it has been granted him from the Father. 66As a result of this many of His disciples withdrew and were not walking with Him anymore.