R. Mordecai Ze’ev ben Isaac Aaron Segal Ettinger (1804-63) was a Polish rabbinic scholar, scion of a long line of rabbis. He studied under R. Naphtali Hirsch Sohastov of Lemberg and under his uncle R; Jacob Ornstein. Although renowned for his scholarship R. Ettinger never occupied a rabbinic position, his considerable personal fortune rendering him independent. He did serve as “nasi of the Holy Land” of the Austrian Kolel, an honorable position always given to the greatest of rabbis. He studied together with his brother-in-law R. Nathanson, many joint works resulting from their 25 years of collaboration. Their partnership ended after R. Ettinger published a ban against machine baked matzah whereupon R. Nathanson published a contrary opinion. R. Ettinger subsequently published several works with his son, R. Isaac Aaron. R. Joseph Saul ha-Levi Nathanson (1810-75) was known as a profound talmudist and as a great posek. He corresponded with all the leading contemporary writers, among them R. Akiva Eger and R. Moses Sofer (Hatam Sofer).
הפנים הוא שולחן ערוך אורח חיים, סי' נח-רלט, ולצידו "אלף המגן" (פירוש קצר) ו"שלטי הגבורים" (פירוש ארוך).