Guide for the Perplexed, by Moses Maimonides, Friedländer tr. , at sacred-texts.com
THE Hebrew term aḥor is a homonym. It is a noun, signifying "back." Comp. "Behind (aḥare) the tabernacle" (Exod. xxvi. 12); "The spear came out behind him (aḥarav)" (2 Sam. ii. 23).
It is next used in reference to time, signifying "after"; "neither after him (aḥarav) arose there any like him" (2 Kings xxiii. 25) "After (aḥar) these things" (Gen. xv. 1). In this sense the word occurs frequently.
The term includes also the idea of following a thing and of conforming with the moral principles of some other being. Comp. "Ye shall walk after (aḥare) the Lord, your God" (Deut. xiii. 5); "They shall walk after (aḥare) the Lord" (Hos. xi. 10), i.e., follow His will, walk in the way of His actions, and imitate His virtues: "He walked after (aḥare) the commandment" (ib. v.11). In this sense the word occurs in Exodus xxxiii. 20, "And thou shalt see my back" (aḥorai); thou shalt perceive that which follows me, is similar to me, and is the result of my will, i.e., all things created by me, as will be explained in the course of this treatise.