[1] After his parents were killed in 1655 during the aftermath of the Chmielnicki massacres of 1648, he moved to live and study with his relative in Leszno, Jacob Isaac Gombiner.
He is known to scholars of Judaism for his Magen Avraham commentary on the Orach Chayim section of Rabbi Joseph Karo's Shulchan Aruch, which he began writing in 1665 and finished in 1671.
His son Chaim wrote in the preface to the work that his father was frequently sick and suffered pain and discomfort.
His lasting effect on halakhah was the incorporation of the Kabbalistic customs of Safed, especially those found in Rabbi Isaiah Horowitz's Shene Luhot Haberit.
In the case of the blessing of "giving strength to the weary" he writes that one does not undo an old custom, and believed that opponents like Rabbi Yosef Karo likely repented of changing minhag at the end of his life.
[8] He taught that aliyot should be given based on events in congregants' lives, such as marriage, birth, and death, rather than always giving it to the scholars.
Yechiel Michel Epstein’s Aruch HaShulchan and Yisrael Meir Kagan’s Mishnah Berurah relied on Gombiner for their acceptance of Kabbalistic practices.
Magen Avraham is notable as being the first work to bring the kabbalistic traditions of the Arizal into the mainstream of halachic discussion.