My question is a) what is a Sefer, b) what is the Sfas Emes and c) who/what is Seferis?
Many thanks in advance for your attention!
A sefer is a book, though in the connection of Jewish texts it usually refers to a book of Torah writings, which has a certain sanctity.
Sefas Emes is the name of the book of Rabbi Yehudah Arieh Leib Alter (1847-1905), the former Grand Rabbi of the Gur Hassidut (after his passing, his son took over the leadership of the Hassidut, followed by three of his grandsons, and currently by a great-grandson).
It is a renowned and much studied commentary on the Torah, which is based mainly on kabbalah (esoteric).
Seferis: Don’t know the word, and it has perhaps been misspelled.