After Birkat Ha-mazon, we drink the third cup of wine and then pour the fourth cup, over which we recite Hallel and “the Great” Hallel (“Hallel Ha-gadol”). Before Hallel we recite the paragraph “Shefokh Ĥamatkha” (“Pour Your Wrath”). Some customarily open the door at this point to demonstrate that, on this night, we are protected against destructive forces and not afraid of our enemies. By virtue of this faith, the Mashi’aĥ (Messiah) will come and pour out his wrath upon the wicked enemies of Israel (Rema 480:1). Some have a custom to stand while reciting Shefokh Ĥamatkha (AHS ad loc., and this was the practice of Rav Kook). After reciting Shefokh Ĥamatkha, we close the door.
We then continue with the second part of Hallel (see above, section 20). There is a mitzva to recite verses 1-4 and 24-25 of Tehilim 118 responsively, led by the eldest member of the household. There is a mitzva to ensure that three adults are present in order to recite the verses in this manner, with one leader and multiple respondents (Rema 479:1). This is all le-khatĥila; of course, an individual fulfills the mitzva even by reciting Hallel alone. If only two people are present, they should recite the verses together (MB 479:10-11).
After this, we recite the Great Hallel (chapter 136 of Tehilim) followed by Nishmat Kol Ĥai (“The Soul of All Life”) and the concluding berakha. There are different opinions regarding the formula of the concluding berakha: Sephardim close with the paragraph “Yehallelukha,” which concludes the normal recitation of Hallel. Ashkenazim close with “Yishtabaĥ,” which concludes the psalms of praise recited at Shaĥarit (see section 31 above, where we learned that it is better to complete this berakha by midnight). Following this, we sing various songs composed in the period of the Rishonim.
Logic dictates that the fourth cup should be drunk right after the concluding berakha of Hallel, which also concludes the Seder that was instituted by the Sages in the times of the Mishna. The songs and poems that follow are merely a custom. Nevertheless, some drink the fourth cup after singing a few of these additional songs, so that they too are sung over a cup of wine and are thus included in the Seder (see MB 480:6). Each family should continue its own tradition.
The Sephardic custom is not to recite “ha-gefen” before the fourth cup, whereas the Ashkenazic custom is to recite it (see section 21 above). After the fourth cup, the berakha aĥarona of “Al Ha-gefen” is said.