Now He said this to indicate the kind of death He was about to experience [i.e., of being lifted up on a cross].
This he said, signifying what death he should die.
He said this to signify in what manner He would die.
But this he said, signifying by what manner of death he should die.
He said this to show how he was going to die.)
(Now he said this, signifying what kind of death he would die.)
(Now this he said, signifying what death he should die.)