The Sanskrit compound means “descent from the realm of the devas” and refers to the Buddha’s return to earth from the Heaven of the Thirty-Three, where he had taught the Abhidharma to his mother during a monsoon retreat. Here it is a toponym for the city or country of Sāṃkāśya, where this event is said to have taken place (see Edgerton, BHSD, s.v. “Sāṃkāśya”).