Guide for the Perplexed, by Moses Maimonides, Friedländer tr. , at sacred-texts.com
Ḥai ("living") signifies a sentient organism (lit. "growing" and "having sensation"), comp. "Every moving thing that liveth" (Gen. ix. 3); it also denotes recovery from a severe illness: "And was recovered (va-yeḥi) of his sickness" (Isa. xxxviii. 9); "In the camp till they recovered" (ḥayotam) (Josh. v. 8); "quick, raw (ḥai) flesh" (Lev. xiii. 10).
Mavet signifies "death" and "severe illness," as in "His heart died (va-yamot) within him, and he became as a stone" (1 Sam. xxv. 37), that is, his illness was severe. For this reason it is stated concerning the son of the
woman of Zarephath, "And his sickness was so sore, that there was no breath left in him" (1 Kings xvii. 17). The simple expression va-yamoth would have given the idea that he was very ill, near death, like Nabal when he heard what had taken place.
Some of the Andalusian authors say that his breath was suspended, so that no breathing could be perceived at all, as sometimes an invalid is seized with a fainting fit or an attack of asphyxia, and it cannot be discovered whether he is alive or dead: in this condition the patient may remain a day or two.
The term ḥai has also been employed in reference to the acquisition of wisdom. Comp. "So shall they be life (ḥayyim) unto thy soul" (Prov. iii. 22); "For whoso findeth me findeth life" (ib. viii. 35); "For they are life (hayyim) to those that find them" (ib. iv. 22). Such instances are numerous. In accordance with this metaphor, true principles are called life, and corrupt principles death. Thus the Almighty says, "See, I have set before thee this day life and good and death and evil" (Deut. xxx. 15), showing that "life" and "good," "death" and "evil," are identical, and then He explains these terms. In the same way I understand His words, "That ye may live" (ib. v. 33), in accordance with the traditional interpretation of "That it may be well with thee" [scil. in the life to come] (ib. xxii. 7). In consequence of the frequent use of this figure in our language our Sages said, "The righteous even in death are called living, while the wicked even in life are called dead." (Talm. B. Berakkoth, p. 78). Note this well.