Guide for the Perplexed, by Moses Maimonides, Friedländer tr. [1904], at sacred-texts.com
WE have already remarked that when we treat in this work of homonyms, we have not the intention to exhaust the meanings of a word (for this is not a philological treatise); we shall mention no other significations but those which bear on our subject. We shall thus proceed in our treatment of the terms ‘alah and yarad.
These two words, ‘alah, "he went up," and yarad, "he went down," are Hebrew terms used in the sense of ascending and descending. When a body moves from a higher to a lower place, the verb yarad, "to go down," is used; when it moves from a lower to a higher place, ‘alah, "to go up," is applied. These two verbs were afterwards employed with regard to greatness and power. When a man falls from his high position, we say "he has come down," and when he rises in station "he has gone up." Thus the Almighty says, "The stranger that is within thee shall get up above thee very high, and thou shalt come down very low" (Deut. xxviii. 43). Again, "The Lord thy God will set thee on high (‘elyon) above all nations of the earth" (Deut. xxviii. 1): "And the Lord magnified Solomon exceedingly" (lema‘alah) (1 Chron. xxix. 25). The Sages often employ these expressions, as: "In holy matters men must ascend (ma‘alin) and not descend (moridin)." The two words are also applied to intellectual processes, namely, when we reflect on something beneath ourselves we are said to go down, and when our attention is raised to a subject above us we are said to rise.
Now, we occupy a lowly position, both in space and rank in comparison with the heavenly sphere, and the Almighty is Most High not in space, but with respect to absolute existence, greatness and power. When it pleased the Almighty to grant to a human being a certain degree of wisdom or prophetic inspiration, the divine communication thus made to the prophet and the entrance of the Divine Presence into a certain place is termed (yeridah), "descending," while the termination of the prophetic communication or the departure of the divine glory from a place is called ‘aliyah, "ascending."
The expressions "to go up" and "to go down," when used in reference to God, must be interpreted in this sense. Again, when, in accordance with the divine will, some misfortune befalls a nation or a region of the earth, and when the biblical account of that misfortune is preceded by the statement that the Almighty visited the actions of the people, and that He punished
them accordingly, then the prophetic author employs the term "to descend": for man is so low and insignificant that his actions would not be visited and would not bring punishment on him, were it not for the divine will: as is clearly stated in the Bible, with regard to this idea, "What is man that thou shouldst remember him, and the son of man that thou shouldst visit him" (Ps. viii. 5).
The design of the Deity to punish man is, therefore, introduced by the verb "to descend": comp. Go to, let us go down and there confound their language" (Gen. xi. 7) "And the Lord came down to see" (Gen. xi. 5); "I will go down now and see" (Gen. xviii. 21). All these instances convey the idea that man here below is going to be punished.
More numerous, however, are the instances of the first case, viz., in which these verbs are used in connection with the revelation of the word and of the glory of God, e.g., "And I will come down and talk with thee there" (Num. xi. 17); "And the Lord came down upon Mount Sinai (Exod. xix. 20); "The Lord will come down in the sight of all the people (Exod. xix. 11); "And God went up from him" (Gen. xxxv. 13); "And God went up from Abraham" (Gen. xvii. 22). When, on the other hand, it says, "And Moses went up unto God" (Exod. xix. 3), it must be taken in the third signification of these verbs, in addition to its literal meaning that Moses also ascended to the top of the mount, upon which a certain material light (the manifestation of God's glory) was visible; but we must not imagine that the Supreme Being occupies a place to which we can ascend, or from which we can descend. He is far from what the ignorant imagine.