। ॥ ६०५ ॥
In plain words
Because you recognize it again, it can be reached only through a trace — nothing more direct. And what memory holds did exist. This is the trace: "I slept well."
Close to the Sanskrit
Because of being recognized again, it is made known by a mere mark alone; the real existence of that which is remembered [follows]. This [is the mark]: 'I slept happily.'