  Indeed, Sa‘adiah’s Beliefs and Opinions is the only extant, substantive work on Jewish philosophy that Ibn Ezra mentions by name. The citation occurs at the very end of the first chapter of Yesod Mora; Ibn Ezra observes that some portions of Sa‘adiah’s book are correct, but others are baseless. However, he never tells us exactly which portions are acceptable and which not, nor does he engage Sa‘adiah in a pointed debate on any issue. Throughout his opus, but most notably in his biblical commentaries, Ibn Ezra mentions Sa‘adiah dozens of times; though he rarely mentions the specific source, he seems to be referring most often to Sa‘adiah’s own biblical commentaries. On the basis of this statistic, at least, Sa‘adiah is, as noted above, the most important “influence” upon Ibn Ezra.