When Avraham wanted Eliezer to swear, he asked the servant to “put your hand under my thigh.”
Today, we are familiar with the idea that when people swear, they place their hand on a holy book (like holding a Sefer Torah), as a means of strengthening the vow and saying they won’t defile the sanctity of the book by being deceitful.
Avraham did a similar thing here. “Under my thigh” was a euphemism for Avraham’s mila, the circumcision he had done at Hashem’s command.
Because he utilized this part of his body for a mitzvah, it became sanctified.
An amazing lesson comes out of this:
We can infuse things with spirituality and holiness, and they remain that way.
We learned previously that Avraham went back to pray where he had prayed before. This is because that spot had been used for a mitzvah, became elevated and more conducive to future prayer.
If we serve Hashem with our bodies, speaking properly, running to mitzvos, and extending our hands to those who need help, we are cultivating holiness within ourselves.
When we use objects or places for mitzvos, they became sanctified and uplifted.
Avraham is teaching us to never underestimate the power we have to make the world, and ourselves, holier.
