I do not know or care if anyone else doubts that he said it, but it is a fact that only one person ever claimed to have heard it and only wrote it down twenty two years later!

the occupation of Palestine as having "stolen their land" significant -

No. Not in 1956.
Israel was created by the UN just nine years previously.
If anyone had stolen the land it was the UN.

Arab armies tried to steal all the Jewish land when they attacked Israel on its first day of existence, and kept on trying for decades.
That is significant.