Sentence:  We find ourselves once more in the presence of the phenomenon "shath", the <WSD>interversion</WSD> of personalities occurring in the course of mystical union. God concedes His part to the ecstatic soul which becomes His mouthpiece; the latter can do no other than speak in the first person, or rather it is God speaking, as it were, by his mouth. 
Meaning of the word marked with <WSD> tags:  The swapping of positions within a sequence; transposition or permutation.