[The cycle of Torah readings] is interrupted for the festivals and Yom Kippur. [On these occasions,] we read [a passage that] concerns the festival and not the sidrah of [that] Sabbath.
Moses instituted [the practice that], on each festival, the Jews should read [a passage] appropriate to it. Also, it [is proper] on each festival to ask about and explain the subjects [pertinent] to that festival.
Which [passages] are read? On Pesach, [we read] the passage concerning the festivals in Leviticus (23:4-44). [However,] the people have already adopted the custom of reading Mishchu uk'chu lachem (Exodus 12:21-51) on the first day. The haftarah is [the description] of the Pesach celebrated in Gilgal (Joshua 5:2-15).
On the second day, we read Shor o kesev (Leviticus 22:26-23:44). The haftarah is [the description] of the Pesach celebrated by Josaiah (II Kings 1-9, 21-25). On the third day, we read Kadesh li kol b'chor (Exodus 13:1-16); on the fourth day, Im kessef talveh (Exodus 22:24-23:19); on the fifth day, P'sol lecha (Exodus 34:1-26); on the sixth day, Vaya'asu Bnei Yisrael et hapesach b'mo'ado (Numbers 9:1-14).
On the final festival, [we read] from Vay'hi beshalach until the conclusion of the song [sung at Red Sea] until [the verse,] Ani Ado-nai rof'echa (Exodus 13:17-15:26). The haftarah is Vayedaber David (II Samuel 22:1-51).
On the eighth day, [we read], Kol hab'chor (Deuteronomy 15:19-16:17). The haftarah is Od hayom (Isaiah 10:32-4, 11:1-16, 12:1-6).