Generally, no doubt, the phrase means an angelic denizen of heaven. The LXX. translates watcher by "angel." Theodotion, feeling that there is something technical in the word, which only occurs in this chapter, renders it by εἴρ. This is the first appearance of the term in Jewish literature, but it becomes extremely common in later Jewish writings--as, for instance, in the Book of Enoch. The term "a holy one"[386] connotes the dedicated separation of the angels; for in the Old Testament holiness is used to express consecration and setting apart, rather than moral stainlessness.[387] The "seven watchers" are alluded to in the post-exilic Zechariah (iv. 10): "They see with joy the plummet in the hand of Zerubbabel, even those seven, the _eyes_ of the Lord; they run to and fro through the whole earth." In this verse Kohut[388] and Kuenen read "watchers" (_'îrîm_) for "eyes" (_'înîm_), and we find these seven watchers in the Book of Enoch (chap. xx.). We see as an historic fact that the familiarity of the Jews with Persian angelology and demonology seems to have developed their views on the subject. It is only after the Exile that we find angels and demons playing a more prominent part than before, divided into classes, and even marked out by special names. The Apocrypha becomes more precise than the canonical books, and the later pseudepigraphic books, which advance still further, are left behind by the Talmud. Some have supposed a connexion between the seven watchers and the Persian _amschashpands_.[389] The _shedîm_, or evil spirits, are also seven in number,-- "Seven are they, seven are they! In the channel of the deep seven are they, In the radiance of heaven seven are they!"[390] It is true that in Enoch (xc. 91) the prophet sees "the first six white ones," and we find six also in Ezek. ix. 2. On the other hand, we find seven in Tobit: "I am Raphael, one of the seven holy angels which present the prayers of the saints, and which go in and out before the glory of the Holy One."[391] The names are variously given; but perhaps the commonest are Michael, Gabriel, Uriel, Raphael, and Raguel.[392] In the Babylonian mythology seven deities stood at the head of all Divine beings, and the seven planetary spirits watched the gates of Hades.[393]