I've noticed in several threads, the construction, "God cannot [do this or that]", even quoted from the Bible. I've typically argued that the meaning, as applied to God in those cases, is that of, "it is illogical (or silly, etc) to think that God would do such a thing". Here, the Lord says, '
“How can Satan drive out Satan? 24 If a kingdom is divided against itself, that kingdom cannot stand. 25 If a house is divided against itself, that house cannot stand. 26 And if Satan opposes himself and is divided, he cannot stand; his end has come.' Notice the construction of the first sentence. It says, "How can Satan drive out Satan?". Pretty obviously, Jesus is not saying that Satan is not in charge of his unruly minions; he's not saying that Satan lacks the power to throw his own demons out. It is not that Satan can't. It's that it would not serve Satan's purposes to do so.
For years, I've thought that construction doesn't make sense. If Satan wanted to deceive people I have no doubt he could replicate this particular ability to "cast out demons". Jesus' explanation bears me out. It is not that Satan can't, but, rhetorically, that if he did it would not help him.
What the preacher here says, is what brought it to mind, as I agree and tend to say, parables are for a main point and sometimes include secondary points (sometimes delivered sarcastically

) but (in this case) are not to teach about how Satan does things. Anyhow, what he said helped me understand a little better the way that Christ was not speaking to Satan's ability, but the foolishness of Satan doing such a thing, and that, rhetorically, and toward the larger point.
In modern day speech/writing, when one might retort to another (me) saying that God is not limited, with "NOT LIMITED! ARE YOU STUPID??? HE CANNOT LIE —IT SAYS SO RIGHT HERE!!!" And, or course, my answer is, "That does not limit God; it's saying that it is an impossible (self-contradictory) construction, to suppose that God WOULD lie."