Eugenio Pacelli practiced the Jewish Shabbat

In 1938, now a physician Dr. Mendes was fired due to the Italian racial laws. Cardinal Pacelli wanted to hire him and move him to Argentina for safety. Mendes chose to go to Palestine instead. It was Cardinal Pacelli who sent him to Switzerland and arranged for the necessary visas for his immigration to Palestine.
Ambassador Meir (Michael) Mendes, son of Dr. Guido Mendes, wrote this book in French, describing the lifesaving efforts of Cardinal Pacelli. In 1983, the book was published in Hebrew by Hebrew University
Source: Pope Pius XII and World War II: The Documented Truth