Rabbi Shimon Bar Yochai

“ By fear and love, by Y"H, darkness and sadness are driven from them. And therefore (Isa. 63:4) , "Ki-yom nekam b'libi/ Precisely the day [light] is what avenges my heart."
וּבְגִין דָּא אוֹר לְאַרְבָּעָה עָשָׂר בּוֹדְקִין אֶת הֶחָמֵץ לְאוֹר הַנֵּר, וְדָא אוֹר הַנֵּר דְּאִיהִי אוֹרַיְיתָא וּפִקּוּדַיָּא, דְאִתְּמַר בְּהוֹן (משלי ו, כג) כִּי נֵר מִצְוָה וְתוֹרָה אוֹר, נֵר בְּלִבָּא, אוֹר בְּעַיְינִין, דְּאִיהוּ אוֹר הַנֵּר, בִּדְחִילוּ וּרְחִימוּ בְּי"ה, מִתְעַבְּרִין חֲשׁוֹכָא וְקַדְרוּתָא מִנַּיְיהוּ, וּבְגִין דָּא כִּי יוֹם נָקָם בְּלִבִּי (ישעיה סג, ד) . ”

“ Another thing: B'LiBY is 'LeB Elohim [=Y] (the "heart" of God) , from the work of Creation, and Ten Utterances which are Y [=10] from LBY. And this LB is the heart with which shines that person of whom it says (Ex. 2:2) , "Wa'Ta're otho KY-tov hu/ And she saw him, he was all good." And in it will the Holy Blessed One reveal Himself to Moshe in the Torah in the final Exile, as in the First Redemption, for it says of it (ibid. 3:2) , "Wayyei'ra mal'akh H' elaw b'LaBath-esh/ And the angel of H' appeared to him in (B=2) flame of fire/ ardent-heart." ”

“ And because of this, ohr l'arba`ah `Asar/ The eve (light) of the Fourteenth [of Nissan] , we check the chametz by the light of the lamp, and this is the ohr ha-ner / light of The Lamp, which is the Torah and commandments, of which it says (Prov. 6:23) , "Ki-ner mitzwah w'torah ohr/ For the commandment is a lamp, and the Torah is light." Light in the heart, and light in the eyes, which is light of the Lamp. ”