One verse

Srimad Bhagavatam 11.14.32-33

11.14.32-33

श्रीभगवानुवाच सम आसन आसीन: समकायो यथासुखम् । हस्तावुत्सङ्ग आधाय स्वनासाग्रकृतेक्षण: ॥ ३२ ॥ प्राणस्य शोधयेन्मार्गं पूरकुम्भकरेचकै: । विपर्ययेणापि शनैरभ्यसेन्निर्जितेन्द्रिय: ॥ ३३ ॥

śrī-bhagavān uvāca sama āsana āsīnaḥ sama-kāyo yathā-sukham hastāv utsaṅga ādhāya sva-nāsāgra-kṛtekṣaṇaḥ prāṇasya śodhayen mārgaṁ pūra-kumbhaka-recakaiḥ viparyayeṇāpi śanair abhyasen nirjitendriyaḥ

śrī-bhagavān uvāca
the Supreme Personality of Godhead said
same
having a level surface
āsane
on the seat
āsīnaḥ
sitting
sama-kāyaḥ
sitting with the body straight and erect
yathā-sukham
sitting comfortably
hastau
the two hands
utsaṅge
in the lap
ādhāya
placing
sva-nāsa-agra
on the tip of one’s own nose
kṛta
focusing
īkṣaṇaḥ
the glance
prāṇasya
of the breath
śodhayet
should purify
mārgam
the pathway
pūra-kumbhaka-recakaiḥ
by the mechanical breathing exercises, or prāṇāyāma
viparyayeṇa
by reversing the processes, namely recaka, kumbhaka and pūraka
api
also
śanaiḥ
following the process step by step
abhyaset
one should practice prāṇāyāma
nirjita
having controlled
indriyaḥ
the senses

The Supreme Personality of Godhead said: Sitting on a level seat that is not too high or too low, keeping the body straight and erect yet comfortable, placing the two hands on one’s lap and focusing the eyes on the tip of one’s nose, one should purify the pathways of breathing by practicing the mechanical exercises of pūraka, kumbhaka and recaka, and then one should reverse the procedure (recaka, kumbhaka, pūraka). Having fully controlled the senses, one may thus practice prāṇāyāma step by step.