Yoga Sūtra Chapter Four verse 20

एक समये चोभयानवधारणम् ॥२०॥

eka-samaye ca-ubhaya-anavadhāraṇam ||20||

And both not ascertained at one juncture.

eka - onesamaya - circumstances; appointed or proper time; agreement; regulateca - andubhaya - bothanavadhāraṇa - not ascertained