A negative particle (akin to lo'); not (the qualified negation, used as a deprecative); once (Job 24:25) as a noun, nothing -- nay, neither, + never, no,nor, not, nothing (worth), rather than.
see HEBREW lo'
II. אַל adverb of negation (so Phoenician e.g. CISi.3, 4.5.8, Biblical Aramaic, Sabean (DHMZMG 1875, 596), and in the Ethiopic albo, is not), denying however, not objectively as a fact (like לֹא οὐ), but subjectively as a wish (like μή), expressing therefore a deprecation or prohibition:
a. (a) with a verb, which is then always an imperfect (never an imperative), by preference in the cohortative or jussive mood, where this is in use, and may be of any person or number; Genesis 15:1 and often אַלתִּֿירָא fear not! 22:12 יָָֽדְךָ אַלתִּֿשְׁלַח put not forth thy hand, 37:27 אַלתְּֿהִיבֿוֺ וְיָדֵנוּ and let not our hand be upon him, 21:16 אַלאֶֿרְאֶה let me not look upon the death of the lad! Psalm 25:2 אַלאֵֿבוֺשָׁה let me not be ashamed; with 1 plural (rare) 2 Samuel 13:25; Jeremiah 18:18; Jonah 1:14. In an imprecation: Genesis 49:4 אַלתּֿוֺתַר have not thou the excellency! Psalm 109:12; Job 3:4, 6. Sometimes strengthened by נָא : Genesis 13:8; 18:3 and elsewhere (b) without a verb, (α) 2 Samuel 1:21 let (there be) not dew & not rain upon you! Isaiah 62:6; Psalm 83:1. (β) used absolutely, in deprecation Genesis 19:18; 2 Samuel 13:16 (see below אוֺדָה) 2 Kings 3:13; 4:16; 6:27 (see RVm: but possibly to be explained by Dr§ 152 iii; so Th Ke: hardly as Ew§ 355 b) Ruth 1:13 בְּנֹתַי אַל Nay, my daughters, compare Judges 19:23; (γ) after a preceding imperative Amos 5:14; Joel 2:13; Proverbs 8:10, a jussive 27:2, an infinitive absolute 27:2. (χ) in poetry אַל sometimes expresses vividly the emotion or sympathy of the poet (see Dr§ 56-8); Isaiah 2:9 לָהֶם וְאַלתִּֿשָּׂא and forgive them not! (with a touch of passion), Psalm 41:3; Proverbs 3:25; Job 5:22; Psalm 34:6 (but ᵑ6 ᵐ5 Ew Che here read וּפְנֵיכֶם, probably rightly); 50:3 a may our God come יֶ֫חֱשָרשׁ וְאַלֿ and not be silent! (the psalmist identifying himself with a spectator of the scene 50:2-3,b-c) 121:3 (contrast 121:4 לֹא) Jeremiah 46:6 +.
b. once Proverbs 12:28 joined closely to a substantive (compare לֹא 2 b) to express with emphasis its negation: In the way of righteousness is life, and in the pathway therecf אַלמָֿוֶת there is no-death! i.e. immortality.
c. once Job 24:25 used in poetry as a substantive, And bring my words לְאַל to nought! — N.B. 1 Samuel 27:10 אַל הַיּוֺם, אַלמְּֿשַׁטְתֶּם with the perfect is against all analogy; and either אֶלמִֿי (with ᵐ5. ᵑ9), or better אָן whither? (with ᵑ7 ᵑ6 : see 10:14) must be read.