Guide for the Perplexed, by Moses Maimonides, Friedländer tr. [1904], at sacred-texts.com
Shama‘ is used homonymously. It signifies "to hear," and also "to obey." As regards the first signification, comp. "Neither let it be heard out of thy mouth" (Exod. xxiii. 13); "And the fame thereof was heard in Pharaoh's house" (Gen. xlv. 26). Instances of this kind are numerous.
Equally frequent are the instances of this verb being used in the sense of "to obey": "And they hearkened (shama‘) not unto Moses" (Exod. vi. 9). "If they obey (yishme‘ü) and serve him (Job xxxvi. 11); "Shall we then hearken (nishma‘) unto you" (Neh. xiii. 27); "Whosoever will not hearken (yishma‘) unto thy words" (Josh. i. 18).
The verb also signifies "to know" ("to understand"), comp. "A nation whose tongue, i.e., its language, thou shalt not understand" (tishma‘) (Deut. xxviii. 49). The verb shama‘, used in reference to God, must be taken in the sense of perceiving, which is part of the third signification, whenever, according to the literal interpretation of the passage, it appears to have the first meaning: comp. "And the Lord heard it" (Num. xi. 1); "For that He heareth your murmurings" (Exod. xvi. 7). In all such passages mental perception is meant. When, however, according to the literal interpretation
the verb appears to have the second signification, it implies that God responded to the prayer of man and fulfilled his wish, or did not respond and did not fulfil his wish: "I will surely hear his cry" (Exod. xxii. 23); "I will hear, for I am gracious" (ib. 27); "Bow down thine ear, and hear" (2 Kings xix. 16); "But the Lord would not hearken to your voice, nor give ear unto you" (Deut. i. 45); "Yea, when ye make many prayers, I will not hear" (Isa. i. 15); "For I will not hear thee" (Jer. vii. 16). There are many instances in which shama‘ has this sense.
Remarks will now be presented to you on these metaphors and similes, which will quench your thirst, and explain to you all their meanings without leaving a doubt.