"From the time the Chiddushei HaRashba was printed, no sefer was as great as the Pnei Yehoshua." This was quoted by the Avnei Tzedek in the name of the Chasam Sofer, whose every word was measured and precise without exaggeration.
The Pnei Yehoshua is authored by R’ Yaakov Yehoshua Falk. The sefer came to be when there was a terrible catastrophe in R’ Yaakov Yehoshua’s town when he was 22 years old. A fire ignited a barrel of gun powder which caused a tremendous explosion and subsequent large fire. R’ Yaakov Yehoshua was caught in the wreckage and his life was in extreme danger. At that moment he made a promise to learn the depths of Torah day and night if he managed to survive. He survived. Rav Menachem Mendel from Kotzk testified that R’ Yaakov finished Shas 36 times before he began writing Pnei Yehoshua.
Biographical note:
R’ Yaakov Yehoshua Falk was born in the year 1681 in the town of Reisha, Poland. He was named after his illustrious grandfather who authored the classic Maginei Shlomo which defended Rashi from the arguments of Tosfos against Rashi. The Pnei Yehoshua served as Rav in a number of cities including Lvov, Berlin, Metz, and Frankfurt. He lived in the same era as the Vilna Gaon, Noda BiYehuda, the Chacham Tzvi, Rav Yaakov Emden, and the Pri Megadim.
His word was regarded as law by his peers. He was made famous by the Chacham Tzvi who eventually suggested him as the Rabbinic successor in Lvov. He was visited by the Chid”a during his travels, and in his sefer Shem HaGedolim, the Chid”a writes about his visit, "I merited to be mekabel pnei hashechina for a number of days (referring to the Pnei Yehoshua). His appearance is like that of a Malach Elokim."
