To afflict and cry out before G-d in times of catastrophe

"When you go to war in your land against the adversary who attacks you, then you shall sound an alarm with the trumpets, that you may be remembered before the LORD your God, and be saved from your enemies.

Hebrew

ט וְכִי-תָבֹאוּ מִלְחָמָה בְּאַרְצְכֶם, עַל-הַצַּר הַצֹּרֵר אֶתְכֶם--וַהֲרֵעֹתֶם, בַּחֲצֹצְרֹת; וְנִזְכַּרְתֶּם, לִפְנֵי יְהוָה אֱלֹהֵיכֶם, וְנוֹשַׁעְתֶּם, מֵאֹיְבֵיכֶם.

Greek

9 ἐὰν δὲ ἐξέλθητε εἰς πόλεμον ἐν τῇ γῇ ὑμῶν πρὸς τοὺς ὑπεναντίους τοὺς ἀνθεστηκότας ὑμῖν, καὶ σημανεῖτε ταῖς σάλπιγξιν καὶ ἀναμνησθήσεσθε ἔναντι κυρίου καὶ διασωθήσεσθε ἀπὸ τῶν ἐχθρῶν ὑμῶν.

• Parashah: B'ha'alot'cha
• Sefer HaChinuch: 384
• Mishneh Torah: Times — Fasts

• Numbers 10:9

Enumeration and classification from BibleData. The Greek is the Septuagint reading of the same verse, carried by the source for comparison.