Sutra 1.18

 विरामप्रत्ययाभ्यासपूर्वः संस्कारशेषोऽन्यः॥१८॥
viraama pratyaya abhyasa purva-ha samskaara shayshow nya-ha ॥१८॥
The other kind of samadhi (one-pointedness in meditation) is asamprajnata samadhi, meaning "without any object into which attention is absorbed". Through constant practice all thought recedes into silence. This the point of connection with Pure Consciousness.

Chris Johnson