Related על ברכות 8:3

Workers that were doing [work] by the owner of the house [when they have to say Birkat Hamazon (Grace After Meals)] they say [only] two Berachot (blessings) [instead of the four usual Berachot]. [The way they say Birkat Hamazon is as follows.] He (i.e. the worker) says the first Beracha [in the regular fashion]. [Then] he combines [the Beracha] of Jerusalem (i.e. the 3rd Beracha) with [the Beracha] of the land (i.e. the 2nd Beracha) [into one Beracha], and he seals it off with [the ending of the Beracha] of the land. If [the workers] were doing [the work] for him [and receiving] their meal [as pay, instead of money], or the owner of the house was saying the Birkat Hamazon for them [because he ate together with them, even if they were getting paid money for their work, then] they (i.e. the workers) say [all] four Berachot. [These are] the things during meals regarding which Bet Shammai and Bet Hillel argue. Bet Shammai say, “[When a person makes Kiddush on Friday night,] he says the Beracha for the day [first] and [only] after that he says the Beracha on the wine, because the day causes the wine to be brought out, and since the day already began, however the wine has not been brought out yet [until later that evening].” And Bet Hillel say, “[When a person makes Kiddush on Friday night,] he says the Beracha for the wine [first] and [only] after that he says the Beracha on the day, because it is the wine that causes the holiness of the day to be discussed. [Besides this there is] another explanation. The Beracha for the wine is common and the Beracha for the [Shabbat] day is not common.” And the law follows the words of Bet Hillel.

We pour the cup [of wine, for Kiddush, first] and [only] after that wash hands [before the meal]. ((Because if you say that we wash first, then may be the water that is on the hands will become Tameh, because of the cup [which is Tameh] and it will go back and make the hands Tameh. But rather [we must say that] we pour the cup [of wine for Kiddush] and [only] then wash hands [before the meal].))