In this week’s parshah (Shemos 6:6) the pasuk reveals the four leshonos of geulah: v’hotzeisi, v’hitzalti, v’ga’alti, and v’lakachti. Rashi, in his commentary to Pesachim 99b, tells us that the four cups of wine that we are commanded to drink on Pesach at the Seder correspond to the four leshonos of geulah mentioned above.
Many Achronim point out a seeming contradiction between the aforementioned Rashi and Rashi’s commentary on a later Gemara in that perek. In Pesachim 108a the Gemara says in the name of Rabbi Yehoshua ben Levi that women are obligated in the mitzvah of drinking the four cups of wine because of the rule “Af hein ha’yu b’osah ha’nes – they too were involved in the miracle.” On this Gemara, Rashi explains that the four cups of wine represent the three times that the word “kos” (cup) appears in the pasukim that discuss the Sar Hamashkim’s dream, and one more for bentching – totaling four cups of wine. Rashi has mentioned two different things that the mitzvah of the four cups represents.
The Yifei Einayim, the Nemukei Hagrib, and the Cheshek Shlomo explain that the Yerushalmi (Pesachim, perek arvai, Pesachim halacha 1) and the medrash in Bereishis (Vayeishev 68) quote a machlokes as to what the mitzvah of the four cups of wine corresponds to. Rabbi Yochanan says it corresponds to the four leshonos of geulah, and Rabbi Yehoshua ben Levi says it corresponds to the word kos mentioned in the pasukim regarding the dreams of the Sar Hamashkim. (They additionally point out that in the medrash the names are switched, and that it is a mistake.)
Rashi believed both opinions to be true. Since the later Gemara that obligated women in this mitzvah was quoting the opinion of Rabbi Yehoshua ben Levi, Rashi wrote according to Rabbi Yehoshua ben Levi’s view of what the mitzvah corresponds to – namely, the word kos in the pasuk.
The sefer, Sdei Chemed (volume 7, chametz u’matzah 15:6) quotes a letter written to him by Rabbi Chaim Berlin in which he attempts to answer this question. He quotes a medrash that explains that the four leshonos of geulah correspond to four decrees that Pharaoh decreed upon the Bnei Yisrael.
The first is “Va’yemariru es chayeihem- and they made their lives bitter.” The second: “im bein hu vahamisen oso – if it is a boy you should kill him.” The third: “kol ha’bein ha’yilod ha’yeorah tashlichuhu – every boy that is born must be thrown into the river.” And the fourth: the decree regarding the straw that they had to work. Each one of the four leshonos of geulah was said against one of these decrees. And the Rabbanan instituted the mitzvah of the four cups of wine to correspond the four leshonos of geulah.
All four decrees were applicable to males; however, only two of them applied to females. One could ask why women are obligated in the mitzvah of four cups of wine if they only were affected by two of the decrees that the leshonos of geulah were said for. It is for this reason that when explaining the Gemara that discusses the obligation of women in this mitzvah Rashi switched to a different source for the four cups of wine. The first Gemara was referring to the general obligation in the mitzvah; therefore, Rashi quoted the reason that it corresponds to the four leshonos of geulah. Additionally Rashi could not use the source that he quoted later for the first Gemara because the first Gemara says that we give a poor man wine for this mitzvah from the tomchei (charity). The source that Rashi quoted in the second Gemara said that the fourth cup is for bentching, and we do not give wine from the tomchei for bentching. Therefore Rashi explained in that Gemara that the mitzvah corresponds to the four leshonos of geulah.
In the later Gemara that discusses a woman’s obligation in the mitzvah, Rashi could not use the source of the four leshonos of geulah since it would not apply to women. Thus he wrote another source that does apply to women as well, namely the word kos in the pasukim describing the Sar Hamashkim’s dream.
Rabbi Chaim Berlin wanted to establish a new halacha based on his p’shat. If a woman were to ask for the four cups of wine from charity, we would be obligated to only give her three cups. This is because if we assume that the mitzvah corresponds to the four leshonos of geulah, she should only have two cups since only two decrees affected women. And if we assume that the mitzvah corresponds to the three times that it says the word kos in the pasuk and the fourth is for bentching, we would only give three cups from charity – since charity cannot provide for bentching.