I have not looked at commentaries on this passage, but an idea I have is that the demons might have done this in order to make the owners of the swine mad at Jesus, which it worked.
As for the Aramaic,St. Mark spoke Aramaic, and he either wrote it in Greek while thinking in Aramaic, or he may have chose to quote Jesus exactly as He said it. My theory is that the New Testament authors wrote more than one copy of their accounts and in more than one language, but that’s another conversation.
In Jewish eyes, the sea is metaphorical for evil and danger (there was always the threat of enemies coming from the sea; see, for instance, the Book of Revelation, where in the new heaven and earth there is no longer any sea). Likewise, pigs are unclean animals. Therefore it is spiritually and theologically apt that the Son of Man has divine authority to cast uncleanliness into danger or evil (back to hell?). On a natural level, the pigs could not contain the wildness of the evil spirits - remember that even the men who were possessed were cutting themselves and acting threateningly.
Good question! It points to the Aramaic origins of the evangelist and story, that’s for sure - Mark’s Greek isn’t the best.
Whoever Mark got his account from (St. Peter?) was hugely impressed by this resurrection from the dead. The words of Jesus still resounded in his head and although he might have given his testimony to Mark in Greek, he spoke the words of Jesus as he heard them, in Aramaic.
That’s a peculiar quirk of Mark. There are at least three places in the gospel where Jesus’ words are given in Aramaic first, followed by a translation into Greek: 5:41 (Talitha koum(i) “Little girl, I say to you, rise up”), 7:34 (Ephphatha “Be opened”), and 15:34 (Eloi, eloi, lema sabachthani “My God, my God, why have you forsaken me?”) That’s not counting the Aramaic words scattered in other parts of the gospel like korban or hosanna or abba (the last two are well-known loanwords among Christians anyway).
On one level, we can say that Mark included these phrases because that’s how the first generations of Jewish Christians (or specifically, if we accept the Petrine tradition here, Peter) passed the tradition. The author did not seem to feel the need to remove uncouth ‘foreign’ words yet, unlike the other evangelists. It serves to give the gospel an air of authenticity in that it serves to underscore the historicity of the events Mark was recording.
On another level, we could say that Mark’s retention of these Aramaic phrases may be to serve as a parodic inversion of the nonsense words and incantations uttered by magicians to impel whatever spirit or deity to grant them power to work wonders (barbarous names, stuff like abracadabra or the Ephesia Grammata or even hocus pocus). Thus, although it may seem that Mark is presenting Jesus as a magician uttering gibberish words of power in these two instances, his providing the translation immediately after the phrase deprives it of its ‘magical’ value. Ergo, it is not the words themselves that have power, but the person of Jesus who possesses this power from God; Jesus has no need to manipulate Him by uttering incantations in order to perform mighty deds.
I’ve read a few books by a couple of prominent Catholic priest atheists, and what I understand them to say is that when demons have been known to possess animals, the animals quickly go mad because they do not have the will or intellect that men do to put up any resistance. This might explains the suicidal actions of the swine.