Days in Chabad
Before he was eight years of age the Tzemach Tzedek was already able to navigate the sea of Talmud and poskim. The Alter Rebbe sang the praises of his limitless gifts and his mastery to his own son, the Mitteler Rebbe, and proposed him as a husband for the Mitteler Rebbe’s daughter, Chaya Mushka.
Until he was thirteen, the Tzemach Tzedek’s studies were devoted mainly to Nigleh. Once, however, he was past the age of bar mitzvah, the Alter Rebbe set times to teach him Kabbalah and Chasidus. In 5564, at the tender age of fourteen-and-a- half, he married Rebbetzin Chaya Mushka, daughter of the Mitteler Rebbe.
Other sources indicate that the marriage took place in 5563.