XXXIII. (183) There are also many various fountains of instruction, by means of which most nutritious reasonings have sprung up like the trunks of palm-trees; “for,” says Moses, “they came to Aileim, and in Aileim there were twelve fountains of water and seventy trunks of palm-trees. And they pitched their tents there by the side of the Water.”{55}{#ex 15:27.} The name Aileim is interpreted to mean “vestibules,” a symbol of the approach to virtue. For as vestibules are the beginning of a house, so also are the encyclical preliminary branches of instruction the beginning of virtue, (184) and twelve is the perfect number, of which the circle of the zodiac in the heaven is a witness, studded as it is with such numbers of brilliant constellations. The periodical revolution of the sun is another witness, for he accomplishes his circle in twelve months, and men also reckon the hours of the day and of the night as equal in number to the months of the year, (185) and the passages are not few in which Moses celebrates this number, describing the twelve tribes of his nation, appointing by law the offering of the twelve cakes of shewbread, and ordering twelve stones, on which inscriptions are engraved, to be woven into the sacred robe of the garment, reaching down to the feet of the high-priest, on his oracular dress. (186) He also celebrates the number seven, multiplied by the number ten; at one time speaking of the seventy palm-trees by the fountains, and in other passages he speaks of the elders, who were only seventy in number, to whom the divine and prophetical Spirit was vouchsafed. And again, it is the same number of heifers which are sacrificed at the solemn festival of the feast of tabernacles, {56}{#nu 29:13.} in a regular and proper division and order, for they are not all sacrificed together, but in seven days, the beginning being made with thirteen bulls; for thus, by every day subtracting one till they come to the number seven, the arranged number of seventy is properly completed. (187) And when they have come to the gates of virtue, the preliminary liberal sciences, and have seen the fountains, and the stems of the palmtrees growing by them, they are said to pitch their tents, not by the palm-trees, but by the waters. Why is this? Because those who carry off the prizes of perfect virtue are adorned with palm-leaves and with fillets; but those who are still exercising themselves in the preliminary branches of instruction, as people thirsting for learning, settle themselves by the side of those sciences which are able to bedew and irrigate their souls.