דברי הימים ב לו:כ פירוש: רש״י

and they became vassals to him and to his sons until the reign of the kingdom of Persia And why until the kingdom of Persia? Because until that time, the land was not appeased for its Sabbaths, as it is written (Lev. 26:35): “As long as it is desolate, it will rest.”