81 Pesachim 10/6-9

(6) Up until which point should he recite? The House of Shammai says: Up to 'as a happy mother of children'. The House of Hillel says: Up to 'flint stone into a water-spring', and conclude with the blessing of redemption. Rabbi Tarfon says: 'who redeemed us and our ancestors from Egypt', but without a concluding blessing. Rabbi Akiva says: 'O YHVH our God and God of our ancestors--may we come to reach other seasons and festivals in peace, joyful in the rebuilding of your city, and jubilant in your Temple service, where we will eat from the offerings and Passover sacrifices etc.' until 'Bless you YHVH, Redeemer of Israel.

(7) They mix a third cup; he blesses his meal. [The] fourth [cup] is concluded with Hallel, which he says with the [concluding] blessing. Between these cups, if he wishes to drink, he may drink. Between the third and the fourth [cups], he may not drink.

(8) They may not add an afikoman after the Pesach offering. If a few of them changed [locations], they may eat. If all of them [changed locations], they may not eat. Rabbi Yossi says: if they nod off, they may eat. If they fall asleep, they may not eat.

(9) [Contact with] the Pesach sacrifice after midnight renders one's hands impure. [Contact with] piggul [a sacrifice that becomes unfit, due to the intention of the officiating priest, while offering it, to consume it after its permitted time] or notar [a sacrifice that becomes unfit, due to being left unconsumed until after the time limit for its consumption] renders one's hands impure. [If] one recited a blessing over the Pesach sacrifice, he exempts [himself from the obligation to make a blessing] on [another] sacrifice [that he eats]. If he recited a blessing over [the eating of another] sacrifice, he has not exempted [himself from the obligation to make a blessing] on the Pesach sacrifice - so says Rabbi Yishmael. Rabbi Akiva says, "Neither this nor that [blessing] exempts the other."