Learning Humility from Har Sinai

The 1st mishnah in Pirkei Avot says, משה קבל תורה מסיני. But why is it stated this way? The mishnah should have said at Sinai, not from Sinai; or even from Hashem. The following answer is from the sefer Toldot Yaakov Yosef: When Hashem commanded Moshe to take Bnei Yisrael out of Mitzraim, he tried to turn away from it and basically said, "who am I to do this?" However, by Matan Torah, we find no such struggle from Moshe.

Moshe saw that there were many other great mountains. But Hashem chose Har Sinai, the smallest mountain, upon which to give the Torah. From there Moshe realized that Hashem wanted to give the Torah sepcifically through the lowest and the smallest. Therefore, Moshe did not turn away from the responsibility of giving over the Torah since he viewed himslef as the lowliest and that is why Hashem chose him for the job. That is why the mishnah is worded the way it is; since Moshe got the strength to take on the job of recieving and giving over the Torah from Har Sinai upon seeing that Hashem chose it, the lowliest mountain.