Shortly after Rabbi Menachem Mendel Schneerson, who later became the seventh Lubavitcher Rebbe, arrived in the United States of America in 1941, his father-in-law, the Rebbe Rayatz, requested that he lead a Chassidic gathering, a farbrengen, on the Shabbat preceding every new Jewish month, known as Shabbat Mevarchim. And Rabbi Menachem Mendel did so religiously.
Following the passing of his father-in-law a few years later, though the new Rebbe refused to officially accept the mantle of leadership for an entire year, he continued the tradition of leading the monthly farbrengens, as per the request of his revered father-in-law, of righteous memory.
On one of those occasions, the Rebbe, of righteous memory, said that he was approached by a journalism student shortly after the passing of the Rayatz. The young student asked the Rebbe to briefly describe the Rayatz, his father-in-law. The Rebbe said, "The Rebbe [Rayatz] was privy to the loftiest spiritual heights and yet never forgot the simple people, people's problems, the mundane things in life."
This description, I feel, also profoundly fits our Rebbe, of righteous memory.
The Rebbe was a brilliant Torah scholar, his teachings covering all aspects and strata of Jewish life. Perhaps the Rebbe would have preferred a private life dedicated to study, but instead, he accepted the leadership of the Chabad movement, and dealt with the everyday issues of countless individuals.
The Rebbe never wasted a second and slept very little. He would return home at 7 p.m., 10 p.m., 12 a.m., 1 a.m., after seeing people in private audience. Even at 6 a.m., there were lights on in his house. Though only he and his wife, Rebbetzin Chaya Mushka, lived in the house, there was much movement.
Most nights, the Rebbe would leave his office with a brown paper bag or briefcase filled with requests for blessings, advice, and scholarly questions ranging from Torah law and Talmud to Kabbalah and Chabad philosophy. When the Rebbe returned to his office in the morning, he was ready to respond to each letter. Clearly, the Rebbe could not have rested much at home if he'd returned late the previous night and had already formulated responses to the many letters he took home with him.