In 1250 he was selected by the provincial chapter, sitting in Toledo, to study Oriental languages at a Dominican school which had been founded for the express purpose of preparing its pupils to engage in polemics against Jews and Moors.
In March 1264, he was commissioned, with the Bishop of Barcelona, Raymond of Penyafort, and two other Dominicans, Arnau de Segarra and Pere Gener, to examine the Hebrew manuscripts and books which the Jews, by order of the king, were to submit to them, and to cancel passages deemed offensive to the Christian religion.
Martí has been accused of forgery because of a few of his quotations from Genesis Rabbah, that were not otherwise known; but Leopold Zunz defends him against this charge (Gottesdienstliche Vorträge der Juden p. 300).
Martí was widely read in Hebrew literature,[7] quoting not only from Talmudic and Midrashic works, but from Rashi, Abraham ibn Ezra, Maimonides,[8] and Ḳimḥi.
Another prominent aspect of his contribution was the enumeration and rejection of the "tikkune soferim", alleged corrections made by Jewish scribes on the Biblical text.
Martí directly and publicly charged these emendations upon the Hebrew scribes as "willful corruptions and perversions introduced by them into the sacred text.