Rabbi Aharon Loft: Ein Yaakov & Maamarim & Shaar Yichud veHaEmuna
Ein Yaakov:
Ein Yaakov is a compilation of all the Aggadic material in the Talmud together with commentaries. It was compiled by Jacob ibn Habib and by his son Rabbi Levi ibn Habib.
It is stated in the Tanya (Igeret HaKodesh 23): “Give glory to the Lord…by studying…the inner part (pnimiyut) of Torah, i.e. the Aggada contained in the work Ein Yaakov. For most of the secrets of the Torah are concealed in it…