[3] In a sermon on the Shabbat before the Cossack riots, he admonished members of the Jewish community to be martyred rather than forcibly converted to Christianity.
[4] When the hordes of Khmelnytsky, taking Nemirov, began the work of pillage and massacre, a Cossack concealed Yechiel, hoping that the latter would disclose where the Jews had hidden their wealth.
[2] He was mourned by Rabbis Shabbatai HaKohen and Yom-Tov Lipmann Heller in their elegies for the victims of the Khmelnytsky massacres of 1648–1649.
[3][5] Yechiel was the author of a work entitled Shivrei luḥot ('Fragments of the Tablets'), containing kabbalistic commentary on several Sabbatic sections and the weekly Torah readings given in the Talmud.
The work was published posthumously at Lublin in 1680 by Yechiel's nephew, whose introduction includes Jewish accounts of the Cossacks' Uprising.