About this time he wrote a satire on the Hasidim entitled "Dibre Ẓaddiḳim." Returning to Kremenetz in the same year, he began his "Te'uddah be-Yisrael," a work destined to leave an indelible impression on a whole generation of Ukrainian Jews. It was finished in 1823, but was not published until 1828. The book attempted to solve many problems of contemporary Jewish life in Ukraine. It urged the study of the Scriptures before the Talmud, and the necessity of studying secular languages, particularly that of one's country of residence. It urged also the study of science and literature, and the great importance for the Jews of engaging in agricultural and industrial work. It strongly counselled the abandoning of petty trade and of other uncertain sources of livelihood.