I don't recall him saying that.
I do recall him saying he would support the nominee if he was treated fairly by the Republican Party.
Big difference.
Check out the video link I posted earlier which shows what he actually said. He said he would need to “respect” the nominee in order to support him. He added the “fair” part only weeks later after he reversed his initial position after intense criticism and agreed to support the GOP nominee but with that caveat. And then later he renigged on his pledge claiming he had not been treated fairly, which makes you wonder if he had planned to do that all along. There are a lot of Republicans who don’t think their candidate was treated fairly by Trump. And there are a lot who don’t respect Trump. Either you’re a Republican or you’re not. If you’re going to run as a Republican then you should agree to accept the outcome of the process and support the nominee. If you don’t then you can hardly complain when others treet you the same way.