There is a tradition recorded in the Talmud that after the Babylonian exile Ezra, the Scribe, replaced the ancient Hebrew characters in which the Torah had originally been written by the square characters still in use. Nothing, however, was omitted from or added to the contents of the Torah, when the present forms of the letters were introduced by Ezra. In the scrolls of the Law the letters were not provided with vowel-points and accents; the manner in which the words, phrases, and sentences were to be read was a subject of oral teaching. Also many explanations and details of the laws were supplemented by oral teaching; they were handed down by word of mouth from generation to generation, and only after the destruction of the second Temple were they committed to writing. The latter are, nevertheless, called Oral Law (‏תורה שבעל פה‎), as distinguished from the Torah or Written Law (‏תורה שבכתב‎), which from the first was committed to writing. Those oral laws which were revealed to Moses on Mount Sinai are called ‏הלכה למשה מסיני‎ “Laws given to Moses on Mount Sinai.” There are several passages in the Bible from which it appears that a certain unwritten law must have supplemented the written Law; e.g., when a man was found in the wilderness gathering sticks on the Sabbath-day, the persons who discovered him brought him to Moses. They must have been taught before, that the gathering of sticks constituted a ‏מלאכה‎, labour prohibited on the Sabbath-day, although this had not been distinctly stated in the written Sabbath-laws. Had this not been the case the Sabbath-breaker could not have been put to death, since he would have committed the sin in ignorance. The same can be said of the man who cursed the name of God; he must have known that cursing the name of God was a capital crime; for he would not have been put to death if the Israelites had not yet been taught that death would be inflicted for such an act. The question which the prophet Haggai (ii. 11) addressed to the priests, and the answers which the priests gave, lead to the conclusion that the details of the laws on uncleanness and cleanness (‏טומאה וטהרה‎) must have been known to the priests and the prophets to a greater extent than has been explained in the written Law. Besides, there were many precepts that came at once into force. These must have been fully explained to the people, who were anxious to obey the word of God. All these explanations and the detailed rules with regard to the written Divine precepts of the Pentateuch, together with laws and institutions established in the course of time by the highest authorities of the nation in obedience to the dictates of the Pentateuch, form the contents of the Oral Law.