One who contributes from his wealth for the purpose of writing or publishing a sefer of a Tzaddik –
Behold, at any given time, and in any corner of the world, that a person studies from this sefer, the Tzaddik [on high] evokes merit on behalf of the donor through whom the sefer was disseminated.
—The Rebbe, Igrot Kodesh, vol 2
Haggadah shel Pesach—im Likkutei Taamim, Minhagim uBeurim
Fondly known as "the Rebbe's Haggadah," this two-volume edition includes the original commentary first penned by the Rebbe in 1946, additional commentary added in subsequent years, Chabad Passover customs, and a comprehensive collection of the Rebbe's talks and letters on the Haggadah and Passover.
The Rebbe's Haggadah is considered a masterpiece of precision and succinctness, clearly setting out the order of the Seder, with reasons and explanations that span the entire spectrum of Torah scholarship—from peshat through sod.