prohibition

וַיֹּ֨אמֶר אֵלֶ֤יהָ אֵלִיָּ֙הוּ֙ אַל־תִּ֣ירְאִ֔י בֹּ֖אִי עֲשִׂ֣י כִדְבָרֵ֑ךְ אַ֣ךְ עֲשִׂי־לִ֣י מִ֠שָּׁם עֻגָ֨ה קְטַנָּ֤ה בָהַרִאשֹׁנָה֙ וְהֹוצֵ֣אתְ לִ֔י וְלָ֣ךְ וְלִבְנֵ֔ךְ תַּעֲשִׂ֖י בָּהַאַחֲרֹנָֽה׃

and Elijah said to her “do not be afraid…” 1Kgs 17:13

The particle אַל is used with second person YQTL to give negative commands and to negate the cohortative and jussivevideo or Gesenius §152f.