The Taz says that with the celebration of freedom on the night of Pesach, when one is sitting like a king, drinking wine, with all his finest dishes and delicacies, we are concerned that one could get carried away and become haughty. The Kittel keeps one in check and subtly reminds him of the Yom Hamisa (day of death) when he will be buried in his Kittel (in line with the custom of many Ashkenaim of being buried in their Kittel), thereby ensuring that he retains a proper sense of humility while conducting his Seder. Another reason mentioned by the Malbim is that white is the clothing color of the Malachei Hashoreis, (Ministering Angels) and we act and dress like Malachim on the holy night of Pesach.
Depending on which reason you hold like, if the Kittel (white robe) is distinguished garb like the Malachei Hashoreis, or if it is the clothing of a man who is reminded of death to keep his ego in check, is what determines whether an Avel (one who lost a parent 12 months before Pesach, or a close relative 30 days before Pesach) wears a Kittel at the Pesach Seder. If the function of the Kittel is to keep one in check, then an Avel can wear the Kittel. If the main function is that the Kittel is dignified clothing like the Malachei Hashoreis (Ministering Angels), and represents freedom, then he should not wear it, as it is not befitting for him. Both these reasons are mentioned in the Rema (Hilchos Yom HaKippurim) to explain why we wear a Kittel on Yom Kippur.
The Talelei Oros brings (from the Sefer Laiv Haivri by Rav Akiva Yosef Schlesinger), a commentary on the last will and testament of the Chasam Sofer, that there is a tradition that Techiyas Hameisim (the Resurrection of the Dead) will take place on Pesach. For that reason, we read the Haftorah on Shabbos Chol Hamoed from Yechezkel which describes the prophecy of the war with Gog U’magog in Tishrei and the Resurrection of the Dead taking place in Nissan.
In fact, the Chazal tell us (Shemos Rabbah 15:2), “In Nissan we were redeemed thousands of years ago, and in Nissan we will once again be redeemed with the Final Redemption” B’Ezras Hashem. Therefore, we wear white clothing to signify that we are ready for the final Geulah which will culminate with Techiyas Hamaisim, Bemhaira Yavo. Wishing all our loyal readers A Gitten Fraylichin Chag Kasher Vesomayach!
