Talmud Torah 3:3
None of the other mitzvos are equal to Torah. Just the opposite, Torah study is equal to all the other mitzvos because study leads to action. Therefore, study takes priority over action.
Talmud Torah 3:4
When a person must choose between performing a mitzvah and studying Torah, if the mitzvah can be performed by someone else, he should not interrupt his Torah study. If no one else can perform the mitzvah, he should do so and then return to his studies.