Yoga Sūtra Chapter Four verse 20
एक समये चोभयानवधारणम् ॥२०॥
eka-samaye ca-ubhaya-anavadhāraṇam ||20||
And both not ascertained at one juncture.
eka - one; alone, solitary, single, happening only once, that one onlysamaya - circumstances; appointed or proper time; agreement; regulateca - andubhaya - bothanavadhāraṇa - not ascertained