On the first anniversary of the Exodus, the Jews are instructed to bring the Paschal Offering. Certain individuals, however, couldn't participate because they were ritually impure. These people lodged a complaint, which Moses then transmitted to G‑d. G‑d responds by designating a "Second Passover" to be observed exactly one month later. Anyone who could not offer the Paschal Offering in its proper time must do so on the Second Passover. G‑d then informs Moses the laws of the Second Passover.