"[...] Phrasing, like other more aesthetic branches [...], is one of those things for which a detailed scheme of instruction cannot well be laid down. It can be demonstrated, violin in hand, but not described. Furthermore, the violinist is characteristically so dependant on the mood of the moment, the accidental influence of temper and disposition, that the same musician seldom plays the same phrase twice in exactly the same manner."
January 1, 1970
https://en.wikiquote.org/wiki/Musical_phrasing