Kabbalah Bilangan 11:18: 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.