"'Previous' is never said. The subsequent statement that this event would take place on that day cannot be heard in the original Arabic version."
If one removes the word "previous" from the translation the idea of the sentence is unchanged so long as the tense of the rest of the statement is accurate. The word "previous" only serves to specify a particular Thursday, rather than any Thursday prior to 9/11.
Allow me to speculate... Biblical Greek is complex compaired with english. A particular word can have modified meaning depending on its position in a sentence, and even the selection and position of the other words in that sentence. This makes the translation process much more complex than simply substituting word for word. Could this be a similar situation with much ado about nothing?