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)
Moreover, one gains purity of sattva, cheerfulness of mind, one-pointedness, mastery over the senses, and fitness for Self-realization.
Source: English translation from Light on the Yoga Sutras of Patanjali (B.K.S. Iyengar)
When the body is cleansed, the mind purified and the senses controlled, joyful awareness needed to realize the inner self, also comes.
Source: How to Know God: The Yoga Aphorisms of Patanjali (Swami Prabhavananda, Christopher Isherwood)
Moreover, one achieves purification of the heart, cheerfulness of mind, the power of concentration, control of the passions and fitness for vision of the Atman.
Source: English translation from The Heart of Yoga (T.K.V. Desikachar)
In addition one becomes able to reflect on the very deep nature of our individual selves, including the source of perception, without being distracted by the senses and with freedom from misapprehension accumulated from the past.
Source: English translation of the Yoga Sutras of Patanjali (Swami Jnaneshvara Bharati)
Also through cleanliness and purity of body and mind (shaucha) comes a purification of the subtle mental essence (sattva), a pleasantness, goodness and gladness of feeling, a one-pointedness with intentness, the conquest or mastery over the senses, and a fitness, qualification, or capability for self-realization.