Yoga and Daoism

There are many parallels between Daoist and Yoga philosophy. For example, from the Kena Upanishad:

यस्यामतं तस्य मतं मतं यस्य न वेद सः ।

yasyāmataṃ tasya mataṃ mataṃ yasya na veda saḥ ।

अविज्ञातं विजानतां विज्ञातमविजानताम् ॥ ३ ॥

avijñātaṃ vijānatāṃ vijñātamavijānatām ॥ 3 ॥

Those by whom Brahman is not known, know it; those by whom it is known, know it not. It is not known by those who know it; it is known by those who do not know it.

— Kena Upanishad, 2.3.

This is immediately reminiscent of what Laozi writes in Daodejing:

道可道，非常道。名可名，非常名。

Dào kě dào, fēicháng dào. Míng kě míng, fēicháng míng.

The Dao that can be trodden is not the enduring and unchanging Dao. The name that can be named is not the enduring and unchanging name.

— Daodejing, chapter 1.