When the holy Reb Uri of Strelisk stated that he reviewed the
laws of taharo 1,000 times, his intention was to
stress the importance of acquiring complete expertise in
HaRav Hillel Vertheimer of Bnei Brak has invested much effort
and hard work to inspire the learning of these laws. He
started by establishing shiurim in his own home,
delivered by HaRav Moshe Shaul Klein, rav of the Or Hachaim
neighborhood and a close disciple of HaRav Shmuel Wosner and
one of the leading morei horo'oh in Eretz Yisroel.
Many of those men who covered the laws together with HaRav
Klein at these shiurim were given permission to
deliver their own shiurim, and some even received
smicha to make halachic rulings regarding
questions of purity.
The chain continued with many new shiurim delivered by
HaRav Klein's graduates sprouting up in different towns in
Eretz Yisroel, and the importance of these laws became
accepted by many.
Gedolei Yisrael praise the shiurim network in a
special letter of appreciation that "in the merit of these
shiurim, many have become more stringent in keeping
these laws." HaRav Shmuel Wosner writes that "my heart and
soul are with those who act and help others; they increase
the honor of Hashem and benefit Jewry."
After the sweeping success of HaRav Klein's shiurim,
HaRav Hillel Vertheimer has proceeded to disseminate this
important information to even more people by printing the
shiurim as a book: Yesod Hataharo. The
sefer is written in a lucid and easy style for all to
understand and is updated in compliance with the rulings of
HaRav Klein's Rebbe, HaRav Shmuel Wosner.
True to its name Yesod Hataharo, the sefer
contains the basic and vital laws of taharo, including
the laws and different customs of each community.
HaRav Moshe Shaul Klein writes in his words of approbation,
"I have toiled to scrutinize every letter in the
sefer, so that the text is clear for every reader and
faithful to the precise meaning of the halacha."
the second part of the book contains the work of HaRav Moshe
Tuvia Dinkel, rav of Bayit Umenucha in Beit Shemesh, which
explains and shows the sources of the laws written in the
The author, HaRav Vertheimer, concludes the book with letters
from gedolei Yisroel from the previous generation,
including HaRav Shaul Brach, the Keren LeDovid of Satmar and
the Chakal Yitzchok of Spinka to the author's grandfather and
namesake, HaRav Hillel Vertheimer Hy"d, concerning the
building of mikvehs.
A call from the present day gedolim to learn and
review hilchos taharo completes the book.
HaRav Steinman and HaRav Lefkowitz write that "all who learn
these laws are guarded from Heaven not to transgress them
HaRav Nosson Gestetner quotes the words of the Kesef Mishna
that, in the World to Come the main rewards for studying
Torah laws are conferred on those who study the laws of
The easy language, the rulings of leading rabbinical
authorities and the organized design of the book mark the
sefer as practical for maggidei shiurim and
rabbonim as well as the layman.