Yōga Sūtra 1.47

निर्विचारवैशारद्येऽध्यात्मप्रसादः।

By 'nirvichāra' samādhi on the topic of ādhyātma (matters related to soul and super-soul) profound knowledge is received with grace.

The 'nirvichāra' samādhi can be obtained on any topic. Great musicians, painters, and workers are in the flow and probably get into samādhi state when they are pursuing their endeavor, where they lose consciousness of time and external world. This will result in special knowledge on the topic being meditated up on. When the topic selected for meditation is ādhyātma, then it results in profound knowledge. 'ādhyātma' in Sanskrit means spiritual pursuit or enquires related to soul (Who am I?) and super-soul (Why and How this universe came in to being?). Here the word prasāda is used, not simple results. Prasāda is received with grace when it is given by the owner. One cannot demand prasāda!