Guide for the Perplexed, by Moses Maimonides, Friedländer tr. [1904], at sacred-texts.com
THE primary meaning of the Hebrew yashab is "he was seated," as "Now Eli the priest sat (yashab) upon a seat" (1 Sam. i. 9); but, since a person can best remain motionless and at rest when sitting, the term was applied to everything that is permanent and unchanging; thus, in the promise that Jerusalem should remain constantly and permanently in an exalted condition, it is stated," She will rise and sit in her place" (Zech. xiv. 10); further," He maketh the woman who was childless to sit as a joyful mother of children" (Ps. cxiii. 9); i.e., He makes her happy condition to be permanent and enduring.
When applied to God, the verb is to be taken in that latter sense: "Thou O Lord, remainest (tesheb) for ever" (Lam. v. 19); "O thou who sittest (ha-yoshebi) in the heavens" (Ps. cxxiii. 1); "He who sitteth in the heavens" (ii. 4), i.e., He who is everlasting, constant, and in no way subject to change; immutable in His Essence, and as He consists of nought but His Essence, He is mutable in no way whatever; not mutable in His relation to other things: for there is no relation whatever existing between Him and any other being, as will be explained below, and therefore no change as regard; such relations can take place in Him. Hence He is immutable in every respect, as He expressly declares, "I, the Lord, do not change" (Mal. iii. 6); i.e., in Me there is not any change whatever. This idea is expressed by the term yashab when referring to God.
The verb, when employed of God, is frequently complemented by "the Heavens," inasmuch as the heavens are without change or mutation, that is to say, they do not individually change, as the individual beings on earth, by transition from existence into non-existence.
The verb is also employed in descriptions of God's relation (the term "relation" is here used as a homonym) to existing species of evanescent things: for those species are as constant, well organized, and unvarying as the individuals of the heavenly hosts. Thus we find, "Who sitteth over the circle of the earth" (Isa. xl. 22), Who remains constantly and unremittingly over the sphere of the earth; that is to say, over the things that come into existence within that sphere.
Again, "The Lord sitteth upon the flood" (Ps. xxix. 10), i.e., despite the change and variation of earthly objects, no change takes place with respect to God's relation (to the earth): His relation to each of the things which come into existence and perish again is stable and constant, for it concerns only the existing species and not the individuals. It should therefore be borne in mind, that whenever the term" sitting" is applied to God, it is used in this sense.