Yoga Sutra 1.31 pain is that by which living beings are struck down,
Pain, frustration, restlessness of the body, spasmodic breathing in or out are the accompaniments of these distractions
The pain is that proceeding from the self, or proceeding from living creatures, or proceeding from the gods. Pain is that by which living beings are struck down, and which they struggle to end. Frustration is the mental agitation when a desire is obstructed. Restlessness of the body is what makes it unsteady and trembling. Spasmodic breathing is inhaling the air from outside, or exhaling the abdominal air. These are the accompaniments of the distractions; they occur in one whose mind is distracted, and do not occur in one whose mind is concentrated in samādhi.
Pain is that by which living beings are struck down, and to end which they struggle, they strive. It is of three kinds, the first being that proceeding from the self (ādhyātmika). What is related (adhy) to self (ātman) is adhyātma, and what arises from that is ādhyātmika. The pain is physical or mental. Physical is caused by disharmony of the humours, etc., and mental is caused by frustration of desires. The second is that proceeding from living creatures (ādhibhautika). Adhibhūti is what relates to (adhi) creatures (bhūta), and what is caused by them is ādhibhautika. And it is what comes about from domestic or wild animals, such as deer and other creatures. The third is that proceeding from the gods (ādhidaivika). Adhideva is what relates to (adhi) the gods (deva), and what comes about from them is ādhidaivika, for instance what is caused by rain and wind. The change of the vowels in these cases is by the rule of grammar that compounds like adhyātma, when they take the -ika suffix, undergo the vṛddhi strengthening in both their parts.
Pain is only one – of the nature of rajas – but it is here classified under the different causes.
Frustration is the mental agitation when a desire is obstructed; it is a baffled moving about.
Restlessness of the body is what makes it unsteady and trembling.
Spasmodic breathing in or out means in the first case drawing in the air in deep gasps but exhaling it slowly, while the second is the reverse.
These are the accompaniments of the distractions in that they are concomitants of distraction. They do not occur in one whose mind is concentrated: to the extent that it is concentrated, to that extent they do not occur.
These distractions which are antagonistic to samādhi are to be inhibited only by that pair, practice and detachment.
The distractions can be inhibited or extinguished only by the pair, practice and detachment. Distractions are unaffected by any other counter-measures. When it is said, in the commentary to I.29, From devotion to the Lord, realization of the separate consciousness and absence of obstacles, that obstacles are inhibited also by a previous devotion to the Lord, it is implied that there is no capacity to become devotees of the Lord without practice and detachment.
He sums up the content of practice in the following sūtra: