From this you learn/ thus you may lear/ it therefore follows
Behold, you have learned. Behold, you have learned. From this it is proven that.
("Is it not true that all the words of the Torah are commanded for us to do forever?" - Harambam/ Sefer Hameda, Hilchot Yesodei Torah, Chapter Nine, 1, 92)
Translation
Expression (Hebrew)
הָא לָמַדְתָּ
Definition (Hebrew)
הִנֵּה לָמַדְתָּ. הֲרֵי אַתָּה לָמַד. מִזֶּה מוּכָח כִּי.
("הָא לָמַדְתָּ שֶׁכָּל דִּבְרֵי תּוֹרָה מְצֻוִּין אָנוּ לַעֲשׂוֹתָן עַד עוֹלָם"- הָרַמְבָּ"ם/ סֵפֶר הַמַּדָּע, הִלְכוֹת יְסוֹדֵי תּוֹרָה, פֶּרֶק תְּשִׁיעִי, א, 92)