Study a single sutra by selecting the pada (chapter) and then the sutra (verse).
Source: English translation from The Yoga Sutras of Patanjali (Sri Swami Satchidananda)
When the senses withdraw themselves from the objects and imitate, as it were, the nature of the mind-stuff, this is pratyahara.
Source: English translation from Light on the Yoga Sutras of Patanjali (B.K.S. Iyengar)
Withdrawing the senses, mind and consciousness from contact with external objects, and then drawing them inwards towards the seer, is pratyahara.
Source: How to Know God: The Yoga Aphorisms of Patanjali (Swami Prabhavananda, Christopher Isherwood)
When the mind is withdrawn from sense-objects, the sense-organs also withdraw themselves from their respective objects and thus are said to imitate the mind. This is known as pratyahara.
Source: English translation from The Heart of Yoga (T.K.V. Desikachar)
The restraint of senses occurs when the mind is able to remain in its chosen direction and the senses disregard the different objects around them and faithfully follow the direction of the mind.
Source: English translation of the Yoga Sutras of Patanjali (Swami Jnaneshvara Bharati)
When the mental organs of senses and actions (indriyas) cease to be engaged with the corresponding objects in their mental realm, and assimilate or turn back into the mind-field from which they arose, this is called pratyahara, and is the fifth step.