dhāraṇāsu ca yogyatā manasaḥ
And the mind is ready for concentration.
Prāṇāyāma prepares you for the next limb of Yoga: dhāraṇāsu (Sūtra 2.29 lists the eight limbs of Yoga in order of gross to subtle: relationships, lifestyle, body, breath, senses, concentration, meditation and complete absorption). Prāṇāyāma is a powerful exercise in concentration (dhāraṇāsu) on the phases of breathing.
As your mind calms through the practice of conscious breathing (prāṇāyāma) and the cloud surrounding our innermost potential is removed (the last sutra refers), you will be able to focus without distraction.
For a detailed guide on the practice of prāṇāyāma see: So what is pranayama? (pranavashyauk.com)
Damian Cadman-Jones is an authorised teacher of Prana Vashya Yoga™