וַיֹּ֣אמֶר יְשַׁעְיָ֗הוּ זֶה־לְּךָ֤ הָאוֹת֙ מֵאֵ֣ת יְהוָ֔ה כִּ֚י יַעֲשֶׂ֣ה יְהוָ֔ה אֶת־הַדָּבָ֖ר אֲשֶׁ֣ר דִּבֵּ֑ר הָלַ֤ךְ הַצֵּל֙ עֶ֣שֶׂר מַֽעֲל֔וֹת אִם־יָשׁ֖וּב עֶ֥שֶׂר מַעֲלֽוֹת׃
At sinabi ni Isaias: “Ito ang magiging tanda para sa iyo mula sa Walang-Hanggan na gagawin ng Walang-Hanggan ang bagay na Kanyang ipinangako: Uusad ba ang anino nang sampung baitang, o babalik ito nang sampung baitang?”
Rashi
and he gave him a sign (ibid. verse 9ff.) “This is your sign, etc.” Everything is delineated there.