The Rebbe's guidance on hiskashrus — a chassid's connection to his Rebbe and to tzaddikim (IK = Igros Kodesh letter number):
What hiskashrus is. True connection to one's Rebbe comes in ascending levels: fulfilling his instructions, partnering in his work, and studying his teachings (IK 662). A Rebbe's directives are Divinely timed and should be acted on promptly (IK 489). Through Chassidus and a deep bond with one's Rebbe, a chassid is never alone (IK 577). The essence of a Chabad Nasi is that he is the channel through which spiritual life flows to his chassidim (IK 635). Hiskashrus means practical faith in the "extension of Moshe" in every generation, which shapes one's daily actions (IK 3406, 2866); the Rebbe is the head, and the attachment to him must be strong (IK 2778). On chassidim's relationship and attitude toward their Rebbe, see IK 2484. The Rebbe's concern about Pesach matzos was not their kashrus but hiskashrus itself (IK 2774). The vital channel of hiskashrus is learning Chassidus (IK 7809, 4392); even one who cannot travel to the Rebbe is united with him through learning Nigleh and Chassidus (IK 3470). Appreciation of the Rebbe must lead to action in Torah and Chassidus (IK 3235). An avrech who has left yeshiva should reconnect with the "tree of life" of Torah and Chassidus (IK 2741). An awakening "from below" must come from one's own initiative, not be requested from others (IK 3244); even a small act of self-sanctification opens the way to great Divine help (IK 1979). One who was privileged to be with the Rebbe and hear his teachings should be reminded of it (IK 1814, 2143, 3517). The Rebbe's "wagon" has room for all chassidim and mekusharim (IK 1795). Maamad is a channel of connection to the Rebbe (IK 1121).
Trust in the Rebbe's care. The Rebbe carries responsibility for his chassidim; trust in his guidance brings calm amid uncertainty (IK 615, 849, 664). The Rebbe's blessings continue in life's most essential matters (IK 2858), and a tzaddik's words carry power (IK 621); revealing the hidden chassid within fulfills the Rebbe's blessings (IK 986). On a father interceding for his son and the title "chassid," see IK 3702; on why a letter was not personally signed, IK 3679; on clarifying that a participation was a suggestion, not an order, IK 2582. Leaving the Rebbe's work to go abroad is cause for concern (IK 10195).
The tzaddik's merit and blessing. The merit of the Rebbe protects and saves all who are connected to him, in times of Torah study and otherwise (IK 4056). Tzaddikim continue to protect and intercede for their followers after their passing; our part is to strengthen the bond through learning their teachings (IK 558). The blessings of tzaddikim have enduring power (IK 8689), and supporting their good deeds connects one to the Tree of Life (IK 2016). A father's involvement in kosher education is a channel for his son's healing, together with strengthening hiskashrus (IK 569); on following medical advice while strengthening hiskashrus, see IK 690. Seeking a blessing for long life is itself a Torah commandment, and the Rebbe gladly prayed for those who asked (IK 3622).
Asking for a blessing. A request for a blessing should include personal details and details of one's observance (IK 1913, 3155); on reporting about a pan submitted, see IK 3069. A petition to the Rebbe is best submitted without any publicity (IK 10345).
Visiting the Rebbe. Visiting one's Rebbe on the festivals, with inner bittul, is of great importance (IK 304), and a proper visit has its conditions (IK 2686); a visit benefits the whole community (IK 10369). On a raffle for plane fare to visit the Rebbe, see IK 3225; on inviting guests to the Rebbe's home, IK 10175. Friends should not pressure anyone to visit when it disrupts their plans (IK 10343).
After a tzaddik's passing. A tzaddik's influence continues after his passing, especially for his chassidim (IK 627), and the connection continues through studying his teachings, joining with fellow chassidim, and fulfilling his directives (IK 703, 654, 7872). On the Tzemach Tzedek's explanation of Malchus of Atzilus and the period after a tzaddik's passing, see IK 600. In the year after a Rebbe's passing, communal Torah study is especially important (IK 868). Teach children about the Rebbe (IK 696). On a tzaddik's yahrzeit the bond grows stronger and his merit brings blessing to those who support his work (IK 8758, 1412, 7945, 893, 3345, 7591, 852); joining in the day of a tzaddik's hilulah, as at a Yud Shevat farbrengen, carries special significance (IK 6687, 8314). On the centennial of the Tzemach Tzedek's passing and the Kerem HaMeah fund, see IK 9120, 9125.
The Ohel and special dates. Mentioning names at the holy resting place brings blessing when paired with connection through Torah and mitzvos (IK 3817, 3426, 6410, 6919, 7310, 8783). Beis Nissan, Rosh Hashanah and other special dates are times to renew one's bond (IK 573, 644, 752); the closeness felt on Pesach should carry through the whole year (IK 7384). Distributing charity funds thoughtfully also strengthens the bond with tzaddikim (IK 7855).
Farbrengens and joining with chassidim. Gatherings where Torah is learned together have great spiritual power, and their resolutions must be fulfilled (IK 2032, 5083, 5143); share the points of a farbrengen with others (IK 2532), report on farbrengens in detail (IK 3298, 6690), and record them for the future (IK 4113). Hold a farbrengen before moving to a new place (IK 1003). Partnering in the Rebbe's work — supporting Merkaz L'Inyonei Chinuch and spreading Chassidus outwardly and inwardly — is part of the connection (IK 706). Learn from everyone and teach others by word and example (IK 745).
See also: Prayer – Praying for others and at the Ohel; Shabbos and holidays – The chassidic holidays; Torah study – Learning Chassidus; Leadership – Farbrengens; Bitachon – Receiving a blessing.