The first quality unique to the mitzva of Torah study not shared by any other mitzva is that whereas action-based mitzvot are chiefly performed using the vital soul’s external garment of action, the mitzva of Torah study is primarily accomplished by using the vital soul’s innermost garments of speech and thought.
In this sense, although the connection with the Divine achieved through Torah study is not as expansive and intense as that attained through the mitzva of charity, it is nevertheless of a loftier and more profound nature.
Giving charity is primarily a physical act, and so the connection to God generated thereby is (relatively) limited by the physical body.
The connection to the Divine formed through the study of Torah, by contrast, is far more profound, for it directly involves human consciousness and not the corporeal body.
There is no other mitzva by which a person becomes so deeply and intimately connected with God.
Rabbi Adin Steinsaltz