Mar Saba maintains a restriction unusual even by the standards of Orthodox male monasticism: women have never been permitted to enter the monastery grounds at any point in its history, a rule tradition traces to Sabbas himself, who is said to have refused even his own mother entry, directing her instead to a tower built outside the walls where female visitors could stay without crossing into the enclosure; a version of that tower, known as the Women's Tower, still stands near the entrance.
The monastery is also at the center of one of modern biblical scholarship's more contested episodes: in 1958 the American scholar Morton Smith reported finding, in the monastery's library, a handwritten copy of a letter attributed to the second century church father Clement of Alexandria, quoting an otherwise unknown longer version of the Gospel of Mark and referring to it as a text kept secret from most Christians. Smith published his findings in 1973, and the text, generally called the Secret Gospel of Mark, has been debated ever since between scholars who accept it as a genuine ancient discovery and others who argue it is a modern forgery, quite possibly by Smith himself; the manuscript Smith photographed has since gone missing from the monastery, leaving the dispute unresolvable by direct re-examination and the matter formally unsettled among specialists.