OK, if Jesus spoke Hebrew then would the meaning of the Hebrew language apply?
All language is communication. It’s immaterial if Jesus was speaking Hebrew to somebody who was Hebrew, or if He was speaking Greek (through John) to people who understood Greek, its the thoughts and concepts that He is attempting to impart that matter. When John said the number of the beast is ‘666’, that would have meant something to Greek readers. Whether it meant something slightly different to Hebrew readers is theoretically possible I suppose, but as they wouldnt be reading it (not understanding Greek) its kind of irrelevant. It is noticeable however that when Revelation was translated into Latin the number of the beast became ‘616’, which kind of ties the number to the meaning, rather than the meaning to the number, as your Hebrew letter/meaning idea would indicate.