Nefesh HaChayim, An Introduction by the Author's Son

But when the situation demanded it he would say things without concealing them. He’d declare to himself: “the main thing is not study, but rather the practice”33Mishna Avot 1:17. And it seems that he was referring to the last part of this Mishna: “…and one who speaks excessively…34This concludes with “…causes sin.”” (these being the words of my teacher, the king35Who is Reb Itzele referring to here?)—that he cites esoteric sources directly36Heb.: sheh-m’ma-leil mee-leen l’tzahd ma-ah-la—paraphrasing Daniel 7:25,37And as concisely and as powerfully relevant as he was able so as to impress those who hear them38Heb.: b’ei-nei ha-shome-im (literally: in the eyes of those who hear)—Here Reb Itzele makes a reference to the experience of synesthesia during the giving of the Torah at Sinai, where Israel “saw the thunder and the flames” (Shemot 20:15). to take them seriously.39Rav Chayyim veered from his normal practice of hiding the deep meanings of what he taught only when the seriousness of how badly people were behaving demanded that he teach using the sources directly. And then he would remind himself that what is critical is how people behave and not the teachings that are used to teach them, and that in certain dire situations it is justified to publicly teach what is not normally taught in public. This was especially so when addressing the Chassidim, who held the Zohar and the writings of the Ariza”l in the highest esteem. By doing so, he would be able to limit to a minimum what he needed to say. Refer to Midrash Shmuel comments on that [for more details]40In Rav di Uzeda’s Midrash Shmuel, near the end of his commentary on this section of Mishna Avot, he quotes Rav Yosef ben Nakh-mee-ahsh: “‘for the body’: for the uneducated masses who are called ‘body’.”.