And behold, we find in the Gemara (Rosh Hashanah 11b) the following language: Rabbi Yehoshua says, in Nissan they were redeemed, and in Nissan they are destined to be redeemed. From where do we know this? The verse states, "a night of watching," a night that has been watched and awaited since the six days of creation. And the other [– Rabbi Eliezer, who disagrees and holds that in Tishrei they are destined to be redeemed, how does he interpret the verse "a night of watching"?], a night watched and protected from harmful forces, end quote.

And this protection from harmful forces is not merely an aggadic [non-legal] statement but a matter of halacha [Jewish law], as we find in the Gemara (Pesachim 109a), where there is no concern on this night for 'pairs' – this is the language of the Gemara, and one should not have fewer than four [– cups of wine]. How could the Sages institute something that brings danger, as it is taught, a person should not eat in pairs, nor drink in pairs, nor wipe in pairs, nor attend to their needs in pairs. Rav Nachman said, the verse states, "a night of watching" – a night watched and protected from harmful forces, end quote.

And the Rema in the laws of the Seder night (Orach Chaim, Siman 480, Seif 1) wrote that this is the reason for the custom to open the door of the house before reciting 'Shefoch Chamatcha' – this is the language of the Rema, and some say to recite 'Shefoch Chamatcha etc.' before 'Lo Lanu,' and to open the door, to remember that it is a night of watching, and in the merit of this faith, the Mashiach will come and pour out his wrath upon those who deny Hashem, and this is the custom, end quote.

By the way, it is worth noting the words of the Rema here, that the reason for the custom of opening the door is not as the common folk think, who believe they do so to allow Elijah the Prophet to enter and drink from the cup prepared for him... Rather, both the opening of the door and the pouring of this additional cup called 'Elijah's Cup,' their reason is as mentioned above, to show our faith that this night is a night of watching and there is no need to fear anything. And this is the language of the Mishnah Berurah there (Sk"y), to remember that it is a night of watching – and there is no fear of anything. And it is customary in these countries to pour one more cup than those reclining, and they call it 'Elijah the Prophet's Cup,' to hint that we believe that just as Hashem redeemed us from Egypt, He will redeem us again and send Elijah to announce it to us, end quote.

They tell a humorous story about a simple villager, who, when he opened the door before reciting Shefoch Chamatcha, was surprised to see a goat with a distinguished beard standing before him. In his foolishness, the villager thought that Elijah the Prophet was before him and invited him with great reverence to enter his house. The goat, delighted with the honorable invitation, joyfully climbed onto the beautifully set Seder table, nibbled with pleasure on the holiday delicacies, and dirtied and broke everything in his path, all while the villager stood to the side watching in reverent awe. At a certain point, when the villager felt that all hope was lost, he mustered the courage and respectfully addressed the goat: Please, Reb Eliyahu! I will give you whatever you desire, but please do not break all my Pesach dishes!

Returning to our matter – another example that the protection from harmful forces is not merely an aggadic statement but a matter of halacha can be found in the words of the Rema in another place in the laws of the Seder night, who wrote (Orach Chaim, Siman 481, Seif 2) that: "It is customary to recite only the paragraph of Shema on this night and not the other passages recited on other nights for protection, because it is a night of watching from harmful forces."