Patañjali, who wrote the Yoga Sûtra, is sometimes referred to as the author of Mahâbhâshya (Sanskrit for great commentary), a commentary on Panini’s grammar Astadhyayi.
As this was written in the second century BCE Jung dates the Yoga Sûtra to around the same time. However, it is disputed that Patañjali was also the author of the Mahâbhâshya.
Recent research dates the Yoga Sûtra between 325 and 425 CE.
(See Maas (2006), p. xix; also introduction p. l. 58, ~Carl Jung, Psychology of Yoga and Meditation, Page 11, fn 115
In the East, the guru, i.e., the leader, gives the tschela, i.e., the student, a particular instruction about the object he is to meditate upon. Guru and student are not outlandish peculiarities.
Every moderately educated person in the East has his guru who instructs him in this technique.
It has been this way since ancient times, a form of education practiced by one whose qualifications as a leader are not endorsed by any university. ~Carl Jung, Psychology of Yoga and Meditation, Page 11