וְאֶל־הָעָ֨ם תֹּאמַ֜ר הִתְקַדְּשׁ֣וּ לְמָחָר֮ וַאֲכַלְתֶּ֣ם בָּשָׂר֒ כִּ֡י בְּכִיתֶם֩ בְּאָזְנֵ֨י יְהוָ֜ה לֵאמֹ֗ר מִ֤י יַאֲכִלֵ֙נוּ֙ בָּשָׂ֔ר כִּי־ט֥וֹב לָ֖נוּ בְּמִצְרָ֑יִם וְנָתַ֨ן יְהוָ֥ה לָכֶ֛ם בָּשָׂ֖ר וַאֲכַלְתֶּֽם׃
또 백성에게 이르기를 너희 몸을 거룩히 하여 내일 고기 먹기를 기다리라 너희가 울며 이르기를 누가 우리에게 고기를 주어 먹게 할꼬 애굽에 있을 때가 우리에게 재미 있었다 하는 말이 여호와께 들렸으므로 여호와께서 너희에게 고기를 주어 먹게 하실 것이라
Sha'arei Kedusha
From this we see that when a Chassid is occupied in the study of Torah or in performing the mitzvot or in good character traits; if even a hint of motivation to receive a reward is mixed into it, he is a Chassid for himself, as in the verse,72Proverbs 11:17 “A man of kindness (Ish Chessed) brings goodness upon himself.” This is because when he fulfills the mitzvot, he brings goodness upon himself. Therefore, he is called a “Man of Chessed” rather than a “Chassid,” because he does himself the kindness. Only a person whose sole motivation is to do a kindness for his Master can be truly called a “Chassid” and a “Holy Man.” This is because he has become purified from all impurities and has sanctified himself in HaShem’s-יהו"ה holiness, blessed is He. We find that the term קדושה-Kedushah (holiness) means “preparation,” as in the verse,73Numbers 11:18 “Prepare74The word here for “prepare yourselves” is “Hitkadshoo-sanctify yourselves” (התקדשו). yourselves for tomorrow and you shall eat meat.” This is because such a person makes himself the vehicle for HaShem’s-יהו"ה holiness, blessed is He. As mentioned above, rather than caring about his own glory, he only cares about his Master’s glory.