וַיָּ֤חֶל יוֹנָה֙ לָב֣וֹא בָעִ֔יר מַהֲלַ֖ךְ י֣וֹם אֶחָ֑ד וַיִּקְרָא֙ וַיֹּאמַ֔ר ע֚וֹד אַרְבָּעִ֣ים י֔וֹם וְנִֽינְוֵ֖ה נֶהְפָּֽכֶת׃
요나가 그 성에 들어가며 곧 하룻길을 행하며 외쳐 가로되 사십 일이 지나면 니느웨가 무너지리라 하였더니
Rashi on Jonah
overturned Destroyed. [He did not say, “Destroyed,” because “overturned” has two meanings, bad and good. If they do not repent, it will be destroyed; if they repent, then “overturned” refers to the people of Nineveh, that they will be changed from bad to good, and they will repent. Gloss of Rabbi Akiva(?)]
Metzudat David on Jonah
started out: when he started his way into the city one day's walk, he proclaimed, "There is still forty days' time", and after that Nineveh will be overturned. That is, like the overturning of Sodom and Gemorrah from existence into nothingness.
Radak on Jonah
Jonah started out: The city was three days' journey from one end to the other. Jonah started by entering the city one day's journey. As he walked, he would call out, "Forty days more and Nineveh is overturned!" That is, like the overturning of Sodom and Gemorrah, because their acts were like theirs.