Mount Sinai, or Jabal Mosá in theological tradition, sacred mountain on which, according to the Old Testament (see Exodus 19), the Hebrew prophet and lawgiver Moses received from Yahweh the tables of the Ten Commandments, or the Decalogue. In other passages of the Bible, it is sometimes called Horeb. Authorities are not in complete agreement over the identification of the biblical Sinai, but most believe that the mountain referred to in the Old Testament is the peak now called Jabal Mosá (Arabic for “Mountain of Moses”). The peak is part of a rocky mass that almost fills the Sinai Peninsula of northeastern Egypt, between the Gulf of Suez and the Gulf of Aqaba. Adjacent to Mount Sinai is Mount Catherine (Jabal Katrīnah), the highest mountain on the Sinai Peninsula. Mount Sinai was regarded as a sacred mountain from ancient times (see Deuteronomy 33:2; Judges 5:5). It became an early center of Christian monasticism when Emperor Justinian I established the Monastery of Saint Catherine at the foot of the mountain in the 6th century; Saint Catherine's was a site of Christian pilgrimage for hundreds of years and remains a functioning monastery.