usually explained as a plural of majesty. In the Hebrew Bible, it is nearly always used to refer to God (approximately 450 occurrences). As pronunciation of the Tetragrammaton came to be avoided in the Hellenistic period, Jews may have begun to drop the Tetragrammaton when presented alongside Adonai and subsequently expand it to cover for the Tetragrammaton in the forms of spoken prayer and written scripture. Owing to the expansion of (the idea of "building a fence around the Torah"), the word "Adonai" itself has come to be too holy to say for Orthodox Jews outside of prayer, leading to its replacement by HaShem ("The Name"). The singular forms and ("my lord") are used in the Hebrew Bible as royal titles, as in the First Book of Samuel, and for distinguished persons. The Phoenicians used it as a title of Tammuz, the origin of the Greek Adonis. It is also used very occasionally in Hebrew texts to refer to God (e.g. Psalm 136:3.) Deuteronomy 10:17 has the proper name alongside the superlative constructions "God of gods" (, literally, "the gods of gods") and "Lord of lords" (, "the lords of lords": ; KJV: "For the your God is God of gods, and Lord of lords"). The final syllable of Adonai uses the vowel , rather than which would be expected from the Hebrew for "my lord(s)". Professor Yoel Elitzur explains this as a normal transformation when a Hebrew word becomes a name, giving as other examples Nathan, Yitzchak, and Yigal. As Adonai became the most common reverent substitute for the Tetragrammaton, it too became considered un-erasable due to its holiness. As such, most prayer books avoid spelling out the word Adonai, and instead write two () in its place. El El appears in Ugaritic, Phoenician and other 2nd and 1st millennium BCE texts both as generic "god" and as the head of the divine pantheon. In the Hebrew Bible, El (, ) appears very occasionally alone (e.g. Genesis 33:20, , "Mighty God of Israel", and Genesis 46:3, , "El the God of thy father"), but usually with some epithet or attribute attached (e.g. , "Most High El", , "El of ", "Everlasting El", , "Living El", "El my Shepherd", and "El of Strength"), in which cases it can be understood as the generic "god". In theophoric names such as Gabriel ("Strength of God"), Michael ("Who is like God?"), Raphael ("God's