Think about this for a few minutes.” The foot – the lowest part of the body – signifies the simplest aspect of our relation to G‑d: submission to His will. In contrast, oil – the source of candlelight – signifies insight (chochmah, in Hebrew), the most sublime faculty of the intellect. Thus, immersing the foot in oil signifies our recognition of the virtue of simple submission over intellect.
The fact that the tribe of Asher “gratified his brothers” by supplying them with olive oil indicates that their attitude toward our relationship with G‑d influenced the other tribes. The deep sense of selflessness that they inspire within us enables us to weather even the most difficult challenges to our faith.1 Likutei Sichot, vol. 1, pp. 102, 107–109.
Moses blessed the tribe of Asher with such an abundance of olive orchards that it would seem as if they were always dipping their feet in olive oil. They would share this abundance of oil with their fellow Jews.
[Moses] said of [the tribe of] Asher: “He will gratify his brothers, for he will immerse his foot in [olive] oil.” Deuteronomy 33:24”