הָרִֽאשֹׁנוֹת֙ מֵאָ֣ז הִגַּ֔דְתִּי וּמִפִּ֥י יָצְא֖וּ וְאַשְׁמִיעֵ֑ם פִּתְאֹ֥ם עָשִׂ֖יתִי וַתָּבֹֽאנָה׃
I have declared the former things from of old; Yea, they went forth out of My mouth, and I announced them; Suddenly I did them, and they came to pass.
Read halakhic rulings (Jewish law) on Isaiah 48:3 from the Mishneh Torah and classical halakhic sources, free online.