In 1818 Firkovitch was hazzan of his native city, an office which among both Karaites and Rabbinites includes that of cantor, reader, teacher, and minister. In 1828 he lived in Berdichev, and had controversies with some Rabbinite Jews, the result being his anti-rabbinical work Masah u-Meribah (Eupatoria, 1838). In later years when he became closely connected with the Rabbinites, he repudiated the sentiments contained in that pamphlet. In 1830 he visited Jerusalem, where he collected many Karaite and Rabbinite manuscripts. On his return he remained two years in Constantinople, as teacher in the Karaite community. He then went to Crimea and organized a society to publish old Karaite works, of which several appeared in Eupatoria with comments by him. In 1838 he was the teacher of the children of Sima Babovich, the head of the Russian Karaites, who one year later recommended him to Count Vorontzov and to the Historical Society of Odessa as a suitable man to send to collect material for the history of the Karaites. In 1839 Firkovich began excavations in the ancient cemetery of Çufut Qale, and unearthed many old tombstones, some of which, he claimed, belonged to the first centuries of the common era. The following two years were spent in travels through the Caucasus, where he ransacked the genizot of the old Jewish communities and collected many valuable manuscripts. He went as far as Derbent, and returned in 1842. In later years he made other journeys of the same nature, visiting Egypt and other countries. In Odessa he became the friend of Bezalel Stern and of Simchah Pinsker, and while residing in Wilna he made the acquaintance of Fuenn and other Hebrew scholars. In 1871 he visited the small Karaite community in Halych, Galicia, where he introduced several reforms. From there he went to Vienna, where he was introduced to Count Beust and also made the acquaintance of Adolph Jellinek. He returned to pass his last days in Çufut Qale, of which there now remained only a few buildings and many ruins. However, Firkovich's house is still preserved in the site.
Firkovich collected a vast number of Hebrew, Arabic and Samaritan manuscripts during his many travels. These included thousands of Karaite and rabbinic documents from throughout the Russian Empire in what became known as the First Firkovich Collection. He was one of the first to visit the Cairo Genizah with the intention of cataloging and studying its contents. His visit, in 1863, took place thirty four years before Solomon Schechter's more famous trip; Firkovich therefore got first pick of the documents contained in the Genizah. Though this "Second Firkovich Collection" contains only 13,700 items in comparison to Schechter's 140,000, the Firkovich documents are generally more complete.
In his later years he became obsessed with "proving" that Crimean Karaites were not Judean in descent, but rather Khazarian; to this end Firkovich resorted to forgeries of tombstones and documents. Because of this, and his secrecy regarding the sources for the Second Collection, any document that passed through Firkovich's hands is academically suspect. His theories, though historically implausible, caught on in the Russian imperial court, and the Karaites were excluded from the restrictive measures against other Jews.
Upon his death in 1874 Firkovich's collection was bought by the Russian National Library.
Among the treasures in the Firkovich collection is a manuscript of the Garden of Metaphors, an aesthetic appreciation of Biblical literature written in Judeao-Arabic by one of the greatest of the Sephardi poets, Moses ibn Ezra.
As the full extent of his forgeries will probably never be known, a list of the genuine and the spurious in the collection is impossible. Briefly stated, the discoveries include the major part of the manuscripts described in Pinner's Prospectus der der Odessaer Gesellschaft für Geschichte und Alterthum Gehörenden Aeltesten Hebräischen und Rabbinischen Manuscripte (Odessa, 1845), a rather rare work which is briefly described in Literaturblatt des Orients for 1847, No. 2. These manuscripts consist of:
The account of the contents of his second and more important collection, which he sold for a very large sum to the Imperial Library of St. Petersburg in 1862-63 (see Fürst, Geschichte des Karäerthums, iii. pp. 174 et seq., Leipsic, 1869), gives more than 700 numbers of various Karaite and Rabbinite manuscripts. Another collection of 317 Samaritan manuscripts, acquired in Nablus, arrived in the St. Petersburg Imperial Academy in 1867 (ib. p. 176).
Probably the greatest service that Firkovich rendered to Jewish science was the awakening of interest in Karaite history and literature, that led to the discussion of his alleged discoveries. His personal contributions to it are mostly of a bibliographical nature, and great caution is necessary in utilizing his materials. His most sympathetic critic, Chwolson, gives as a résumé of his belief, after considering all controversies, that Firkovich succeeded in demonstrating that some of the Jewish tombstones from Chufut-Kale date back to the seventh century, and that seemingly modern forms of eulogy and the method of counting after the era of creation were in vogue among Jews much earlier than had been hitherto suspected. But even on these points the opinions of authorities are far from being unanimous.
S. L. Rapoport has pointed out some impossibilities in the inscriptions (Ha-Meliẓ, 1861, Nos. 13-15, 37); A. Geiger in his Jüdische Zeitschrift (1865, p. 166), Schorr in He-Ḥaluẓ, and A. Neubauer in the Journal Asiatique (1862-63) and in his Aus der Petersburger Bibliothek (Leipsic, 1866) have challenged the correctness of the facts and the theories based upon them which Jost, Julius Fürst, and Heinrich Grätz, in their writings on the Karaites, took from Pinsker's Liḳḳuṭe Ḳadmoniyyot, in which the data furnished by Firkovich were unhesitatingly accepted. Further exposures were made by Strack and Harkavy (St. Petersburg, 1875) in the Catalog der Hebr. Bibelhandschriften der Kaiserlichen Oeffentlichen Bibliothek in St. Petersburg; in Harkavy's Altjüdische Denkmäler aus der Krim (ib. 1876); in Strack's A. Firkowitsch und Seine Entdeckungen (Leipsic, 1876); in Fränkel's Aḥare Reshet le-Baḳḳer (Ha-Shaḥar, vii. 646 et seq.); in Deinard's Massa' Ḳrim (Warsaw, 1878); and in other places. Chwolson alone defended him, but he also was forced to admit that in some cases Firkovich had resorted to forgery. In his Corpus Inscriptiorum Hebraicarum (St. Petersburg, 1882; Russian ed., ib. 1884) Chwolson attempts to prove that the Firkovich collection, especially the epitaphs from tombstones, contains much which is genuine. It must be admitted that Firkovich did much to further the study of Karaite and Crimean Jewish history, and that after all deductions are made his discoveries still remain of great value.
________. “Firkowitsch, (Firkowitz), Abraham ben Samuel.” Encyclopedia Judaica 6: 1017-19.