Updated: Mar 1
" atha yogasusasanam "
atha - now, at this auspicious moment
yoga - arresting of the mind as in samadhi
anu - pursue something already established, tradition
sasanam - discipline, instruction
Patanjali's sutras belong to the era when writing simply for entertainment or commerce was not the norm. Writing was a auspicious trade, writing down something was considered only, when the subject matter of the write up was intended to help the reader attain spiritual realisation. Even when the writings on such subjects were established, they were not intended for a casual reader. Only a person with serious intent of attaining spiritual realisation was meant to be studying, not just reading such manuscripts. The #yogasutras as compiled by Patanjali carry the same earnestness, intent behind studying them.
This sutra if translated to simple English verbatim will mean, " now the study of Yoga begins." The word now has a auspicious significance to it. Now the study begins means such a study or learning has never been undertaken before the present time; the time at which the Sutras were being complied. Secondly the author uses the word study, something which has already been established would just be instructed upon, no new system or tradition is being created here. It is believed that the first living being known as "Hiranyagharbha" had created the original tradition which is now just being revisited by the author, in a more structured manner.
The vibrations associated with the pronunciation of different syllables in Sanskrit are meant to be generating certain auspicious feelings in the human Mind. The word "atha" meaning, now, has the same potential of generating a very auspicious feel inside the speaker: it imparts a sensation of respect to the status of a great teacher whose tradition we are just about to begin studying. Yoga, as mentioned in this sutra means complete control over the Mind, as is in the state of pure Samadhi. It doesn't mean union, joining of two parts into one, as is the literary meaning of this Sanskrit word.
So if we elaborate the meaning of this sutra further it would mean, now we are starting the study, in a more structured manner, or going again on the discipline of arresting the Mind, as it is in the state of Samadhi, originally established by the great teacher (Hiranyagarbha) himself.
Yoga here clearly means a concentrated, focused Mind. This means that Patanjali in the very first sutra establishes his intent of compiling these sutras: learning the techniques of how to arrest the Mind. Mind being central to all his expositions further. This sutra clarifies the entire scheme of yoga.