The Rebbe's guidance on hospitality (hachnasas orchim) and acts of kindness:
A channel for blessing. Hospitality is a spiritual channel for blessing, including for children (IK 790), and together with Torah study, Chassidus and tzedakah it is a merit for having a son (IK 2606). Continue acts of charity and hospitality, for their special merit (IK 2509). Kindness and friendship, especially to relatives in need, are a great mitzvah that G-d repays with success and nachas (IK 908). Like Avraham's eshel, hospitality goes together with tzedakah and spiritual growth (IK 6559).
Hospitality with content. Hosting should include sharing G-d's greatness as explained in Chassidus, which one must first internalize oneself; when spouses disagree about how much to host, consult a Rav (IK 5778). A home run with hospitality, especially in connection with spreading Chassidus or helping a kallah, is the strength of the Jewish woman (IK 8736). Hosting others can deeply influence them even indirectly (IK 1538).
Appreciation. The Rebbe thanked hosts for their hospitality, including at the Pesach Seder (IK 450, 7319), and suggested keeping a guest book for visitors (IK 10570). On hospitality alongside family customs such as checking tefillin and mezuzos, see IK 7330.
See also: Tzedakah – Free loans (gemach) and acts of kindness; Tzedakah – A source of blessing for health, livelihood and family; Women – The role of the Jewish woman.