Мидраш к Вайикра 23:2

1) (Vayikra 23:2) ("Speak to the children of Israel and say to them: The festivals of the L–rd, which you shall call (them) callings of holiness — these are My festivals.") And whence is it derived that the year is intercalated for the sake of those living in exile, (who left their places) and have not yet reached (Jerusalem for the festival)? From "the children of Israel … The festivals of the L–rd" — Arrange the festivals so that they can be observed by all of Israel.

1) Above (Vayikra 23:2), intercalation of the year is being spoken of, and here (Vayikra 22:4) sanctification of the month is being spoken of. If (the moon) were seen clearly, or witnesses came and testified (to that effect) before them (beth-din), and they were unable to proclaim "It is intercalated until it became dark — whence is it derived that it is intercalated? From "which you shall call (them) in their times." If you called them, they are My festivals. If not, they are not My festivals.

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