Friedlaender's most important forgery, his pretended Seder Kodashim of the Jerusalem Talmud with his commentary Heshek Shelomo. Friedlaender proclaimed his fortunate discovery of an ancient Spanish manuscript, dated Barcelona 1212, which contained this long lost and most important talmudic text.
With this publication, he reached the summit of his audacity, claiming to be of pure Sephardi descent (Sephardi tahor) from the well-known Algazi family and a native of Smyrna. He asserted that he was assisted in the acquisition of the manuscript by his brother, Elijah Algazi, and a business associate of the latter, both citizens of Smyrna. Some of the leading scholars of this period, such as Solomon Buber, Solomon Shechter, and R. Shalom Mordecai Schwadron of Brzezany accepted his story. However, the majority of scholars gave no credence to his tales, and R. B. Ritter of Rotterdam conclusively proved the fallaciousness of Friedlaender's claims. On the basis of internal evidence, R. Ritter showed that the text was an overt forgery. R. Ritter's conclusions were supported by many experts, including R. V. Aptowitzer, R. W. Bacher, R. D. B. Ratner and R. Meir Dan Plotzki. The controversy continued for the next few years, and as late as 1913, Friedlaender still published booklets on this issue.
שער נוסף לכל חלק:
La Tosephta ... avec le commentaire: Hosak (Heschek) Schlomoh ... Par le Rabbin Lev Friedlaender a Mulhouse .
עם מבוא, מקצתו בראש זרעים ומקצתו בראש נשים. המבוא נדפס שנית בהוספות ובשינויי עריכה בשם "מבוא לתוספתא", טירנוי תר"ץ, על ידי מאיר פרידלנדר, בנו של המפרש, שבקש להוציא לאור גם את החלקים האחרים של התוספתא עם הפירוש "חשק שלמה". [חלק א]: סדר זרעים. דפוס דוד לוי ואברהם דוד אלקאלאי, תרמ"ט. ל, , 284,  עמ'.