Rahtza surely ranks as the most mundane stage of the entire seder. Not only have we already washed our hands once before, but this second hand washing is simply an application of the year-round halakhic practice of washing one’s hands before eating bread. Rahtza, then, is the one point at which this night is not different than all other nights.

Nor is the significance of this ritual handwashing redeemed by considering its halakhic development. According to the Talmud, handwashing before meals was originally required only for those partaking of sanctified foods, which had to be consumed in ritual purity. Hence it affected mainly priestly families, who would regularly partake of sacrifices and terumah (priestly tithes.) Only as a kind of legislative afterthought did the rabbis expand the requirement to all those partaking of bread, and even then mainly to prevent priestly families from getting mixed up.

Yet as we ponder the banality of this ritual, it is worth recalling that in Temple times, Passover may have been the only occasion in which the original reason for the law actually applied to everyone. At this point in the seder, we would be preparing to eat not only the matza, but with it the paschal sacrifice, the only sacrifice which all Jews were required to eat. For Jews in antiquity, this hand washing would be special, as it marked the meal to come as sacred.

From this perspective, the extension of this law to the rest of the year might be thought of as an act of infusing our everyday activities with a touch of holiness, an extension of the rabbinic adage "A table is akin to the altar.” Rather than considering Rahtza to be the one ordinary part of the seder, we may think of it as the only part of this extraordinary night that we carry with us into the rest of the year.

Rabbi Daniel Reifman teaches Talmud. 

haggadah Section: Rachtzah
Source: Rabbi Daniel Reifman in http://elmad.pardes.org/2016/04/the-pardes-companion-to-the-haggadah/