Halakhah for Chullin 173:41

The laws of the commandment - for example, the Order (Seder) that Israel is obligated to do on this night in the matter of their meal; the cups of wine, their measurements, their pouring and their order; and the rest of their details - are [all] elucidated at the end of Pesachim (See Tur, Orach Chaim 469-482). And behold, my son, I will write for you the Seder in short - exactly as I have heard it from the sages of the generation: In the beginning, we bring water and wash one hand for the sake of the cup of Kiddush which needs to be held. And this is how it is in Berakhot 43a in the Chapter [entitled] Keitsad Mevarkhin - that with the cup, washing one hand is sufficient. And we do not recite a blessing on this washing. And if he wants to wash two hands for the cup, he washes them without a blessing. And afterwards, he washes both hands and recites the blessing, "upon the washing of the hands," and dips with a vegetable (the vegetable, according to the Vilna edition) and recites the blessing, "who creates the fruit of the ground," before [eating it]. But he does not recite the blessing, "who creates souls, etc.," after it - since he waits until he eats the marror; and then he recites the blessing, "who creates souls," upon the marror and upon the vegetable. And everything that he did is not an interruption, as we will explain. And after they ate from the vegetable in charoset (a thick sweet dip), we pour a second cup and read the Haggadah with two chapters of Psalms and recite the blessing, "who has redeemed us, etc.," upon the second cup, and we drink it. And we do not recite the blessing, "who creates the fruit of the vine," upon it, nor "upon the vine," after it. And after they drink the second cup, we wash our hands and recite the blessing, "upon the washing of the hands." And [then] we take half of a matsah and we place it on the complete one and recite the blessing upon the half, "who brings forth" and "to eat matsah." And we take bitter herbs and we recite the blessing, "to eat marror," and eat from it dipped in charoset; but we do not recite the blessing, "who creates the fruit of the ground," upon it, since he is exempted by the blessing that he recited upon the vegetable at the beginning. As this is how it is concluded in the Gemara (Pesachim 103b) - that it is never [considered] an interruption unless there is [one of] two things: That he removes his thoughts from the matter - for example when they say, "Let us bless (say Grace after the Meal)," and similar to it. And also that [he be engaged in something else, such] that it not be possible to do the two things together - for example that which they, may their memory be blessed, said (Chullin 87a and Rashi there), "Drinking and blessing together is not possible." And after we eat from the marror with the dip, we wrap some of it on top of matsah and eat a little bit, in memory of the Pesach sacrifice that was eaten upon satiation. And we do not eat more the whole night, so as not to remove the taste of matsah from the mouth; as it is written (Psalms 113:103), "than honey to my mouth." But we can certainly drink water, since water does not spoil the taste. And we also drink the two cups of the commandment, as we do not push off the commandment [on account of] this reason. And afterwards, we wash our hands, but we do not recite the blessing, "upon the washing of the hands." And we pour the third cup and recite the Grace after the meals and "who has created the fruit of the vine" over it; but not "upon the vine," after it (see Baal HaMeor on the end of Arevei Pesachim). And afterwards, we pour the fourth cup and finish Hallel over it. And we do not recite the blessing, "who has created the fruit of the vine," upon it; but we do recite the blessing, "upon the vine," after it. And that is if he does not have in mind to still drink a fifth cup. It comes out according to this that we only recite the blessing, "who has created the fruit of the vine," twice - on the cup of Kiddush and on the cup of the Grace. And [we only recite the blessing,] "upon the vine," once, after all of the cups. And the four cups and the matsah of the commandment requires leaning.