Please answer the following question: I want to test the ability of students to read a passage and answer questions about it. Could you please come up with a good question for the passage "In the language of the Noble Eightfold Path, samyaksamādhi is "right concentration". The primary means of cultivating samādhi is meditation. Upon development of samādhi, one's mind becomes purified of defilement, calm, tranquil, and luminous."?
A:
__ first appeared in the Maitri Upanisad.