Yoga Sūtra Chapter Four verse 10

तासामनादित्वं चाशिषो नित्यत्वात् ॥१०॥

tāsām-anāditvaṃ cā-āśiṣaḥ nityatvāt ||10||

And the beginninglessness of these
is due to the eternality of primordial desire.

tāsām - of theseanāditva - beginninglessnessca - andāśis - will to live; desire for self-welfare; primordial desire; prayer, wish, asking for; blessing for, benedictionnityatva - invariableness, constancy, continuance, eternity, perpetuity

Commentaries and Reflections

Commentary by S Ramaswami:

“The desire for permanence is always there, proving the beginninglessness of Karma Vāsana.
If you want to trace the course then look to previous Janma, Dharma and Adharma. The whole sequency is maintained by Vāsana appropriate to a particular birth.
As to when it began or which came first the example is given of the tree and the seed. Which came/caused the first, the seed or the tree? What we need to know is whether it can be broken.”