37. As for the statement that 'the lights will be for signs, and for set times, and for days, and for years', this contains more arcana than can be presented at this point, though no arcanum at all is visible in the sense of the letter. For now only this can be said: Change in spiritual and celestial things takes place both on general and on particular scales, and is comparable to changes that take place through the day and through the year. Changes through the day are from morning to midday, from then on to evening, and through the night to the morning. Changes in the year similar, from spring to summer, from then on to autumn, and through winter to spring. These bring changes in temperature and amount of daylight, and so in the fertility of the earth. Compared to such changes are the changes that take place in spiritual and celestial things. Life without changes and variations would lead to sameness, and so no life at all. Good and truth would not be recognized and identified, let alone perceived. In the Prophets such changes are called 'ordinances', as in Jeremiah,

[Thus] said Jehovah who gives the sun for light by day and the ordinances of the moon and of the stars for light by night, These ordinances will not depart from before Me. Jeremiah 31:35-36.

And in the same prophet,

Thus said Jehovah, If I have not established My covenant of day and night, the ordinances of heaven and earth . . . Jeremiah 33:25.

But these things will in the Lord's Divine mercy be dealt with at Genesis 8:12.

10216. 'When you take the sum of the children of Israel' means all things of the Church. This is clear from the meaning of 'the sum' as all; and from the representation of 'the children of Israel' as the Church, dealt with in the places referred to in 9340. The reason why all things of the Church are meant by 'the sum of the children of Israel' is that the internal sense of the Word is the kind of meaning it has in the heavens. Names do not come through to those there, such as the names Israel, Moses, Aaron, and many others; for those names belong to things that are material, which exist solely for the benefit of human life on the level of the physical senses. Instead of those names things on a spiritual level that belong to heaven and the Church are perceived. For angels in heaven are spiritual, and the things that come to their attention they see according to the inner nature of those things, thus on a spiritual level. There in place of the children of Israel they understand the Church. They do so because in the inmost heaven, where the Lord's presence is more immediate than in the heavens below, the Lord Himself is understood by names in the Word, when they are used in a good sense, names such as Abraham, Isaac, Jacob, Moses, Aaron, David, Joseph, Judah, or Israel. And since the angels there understand the Lord by these names, they also perceive - in accord with the train of thought in the Word - the Divine things which belong to heaven and the Church, and are derived from the Lord. The perception flows in from the Lord, who is the Word; for the Lord is the source of all intelligence and wisdom, and none at all exists without Him.