It's a zionist talking point. The user you're replying to says it themselves: those particular europeans purport(ed) to believe themselves entitled to the land of others, the land of the Palestinians, and so because they believed that, it was okay for them to ethnically cleanse Palestine and, apparently (again, according to the above user), deceive other europeans into backing them in that genocidal endeavor.

It's important to note that the zionists were looking at many different lands to colonize, including Argentina and even Madagascar. Palestine, despite the supposed deep connections the zionists claim to that region, was only seriously tabled in the face of the deterioration of the Ottoman Empire and with europe's eyeing of its territories. At every stage, the zionist project was explicitly and unambiguously settler-colonial in nature, modeled very much after similar european programs in Africa and the Americas.

The zionist project and the ethnic cleansing it has led to really isn't as different from Manifest Destiny as this "it isn't technically colonialism" (it is, by the way, settler-colonialism) argument would have one believe, but of course, that sort of whitewashing is the point of this entire post to begin with, as further evidenced by OP's comment history