Joel 2:11-15

11And Jehovah uttereth his voice before his army; for his camp is very great; for he is strong that executeth his word; for the day of Jehovah is great and very terrible; and who can abide it?

12Yet even now, saith Jehovah, turn ye unto me with all your heart, and with fasting, and with weeping, and with mourning: 13and rend your heart, and not your garments, and turn unto Jehovah your God; for he is gracious and merciful, slow to anger, and abundant in lovingkindness, and repenteth him of the evil. 14Who knoweth whether he will not turn and repent, and leave a blessing behind him, even a meal-offering and a drink-offering unto Jehovah your God?

15Blow the trumpet in Zion, sanctify a fast, call a solemn assembly;