וַיֹּ֖אמֶר הִקְשִׁ֣יתָ לִשְׁא֑וֹל אִם־תִּרְאֶ֨ה אֹתִ֜י לֻקָּ֤ח מֵֽאִתָּךְ֙ יְהִֽי־לְךָ֣ כֵ֔ן וְאִם־אַ֖יִן לֹ֥א יִהְיֶֽה׃
And he said: ‘Thou hast asked a hard thing; nevertheless, if thou see me when I am taken from thee, it shall be so unto thee; but if not, it shall not be so.’
Read halakhic rulings (Jewish law) on II Kings 2:10: and classical halakhic sources.