thereby hangs a tale
That detail or incident reminds one of another story, as in So he went without supper, but thereby hangs a tale. This expression, embodying the pun on tail and tale, was used by Shakespeare in at least four of his plays and presumably was well known before that. [1500s]
Words nearby thereby hangs a tale
thereabout,
thereabouts,
thereafter,
thereat,
thereby,
thereby hangs a tale,
therefor,
therefore,
therefrom,
therein,
thereinafter