וַיָּ֤חֶל יוֹנָה֙ לָב֣וֹא בָעִ֔יר מַהֲלַ֖ךְ י֣וֹם אֶחָ֑ד וַיִּקְרָא֙ וַיֹּאמַ֔ר ע֚וֹד אַרְבָּעִ֣ים י֔וֹם וְנִֽינְוֵ֖ה נֶהְפָּֽכֶת׃
And Jonah began to enter into the city a day’s journey, and he proclaimed, and said: ‘Yet forty days, and Nineveh shall be overthrown.’
Read halakhic rulings (Jewish law) on Jonah 3:4: and classical halakhic sources.