וַיֹּ֣אמֶר יְשַׁעְיָ֗הוּ זֶה־לְּךָ֤ הָאוֹת֙ מֵאֵ֣ת יְהוָ֔ה כִּ֚י יַעֲשֶׂ֣ה יְהוָ֔ה אֶת־הַדָּבָ֖ר אֲשֶׁ֣ר דִּבֵּ֑ר הָלַ֤ךְ הַצֵּל֙ עֶ֣שֶׂר מַֽעֲל֔וֹת אִם־יָשׁ֖וּב עֶ֥שֶׂר מַעֲלֽוֹת׃
以賽亞說：「這是永恆者給你的兆頭，表明永恆者必成就祂所說的話：你要日影向前移動十級，還是後退十級？」
Rashi
Should the shade advance ten steps or should it go back ten steps? This is an abbreviated verse. The shade had already advanced the steps that are made [to measure] the hours of the day, like, oriloje, in O. F., the clocks that people make to determine the hour of the day. [He asked,] “Do you wish it to stay in the place where it is, for as long as it takes it to walk in ten hours, or should it go back up ten steps so that it will appear as though it is morning?”7Alternatively, Yeshayohu asked, “Do you wish it to advance or to go back?—Radak