I will list some interpretations of shminis shebeshminis.
1. Rashi, in Tehilim, 119 called Tamyeh Apeh, having eight pesukim for every letter of the aleph beis in the eight letter, ches tne eight pasuk. Thank Hashem for the chesed of knowledge to be able to learn.
2. In Pirkei Avos 6th Perek in the 8th Mishna there are eight words, eigtht character traits, hanoy, vehakoach etc. which contribute to humility according to the Binah Leitim by recognizing that they are provided by Hashem.
3. The GRA, the eight Parasha in the Torah at the eight pasuk, katonti mikol hachasodim recognizing
that all chasodim come from Hashem.
4. The lowest mountain, Har Sinai, is 1/64th of the highest mountain, Har Tabor.
5. My pshat, remembering samach dalet (64) siyata dishmaya, Hasbem’s help, to be able to learn leading to humility.