4th–5th century CE) and later monks, mainly on the basis of earlier materials now lost.
All dates in early Indian history are highly conjectural.
A long-term committed one was all the more an opportunity to go deeper in one’s understanding and cultivation of these qualities.
So then what is non-attachment in a loving, committed relationship?
The traditional Theravādin interpretation is summarized in Buddhaghosa's Visuddhimagga.
the Canon contains everything needed to show the path to nirvāna; the commentaries and subcommentaries sometimes include much speculative matter, but are faithful to its teachings and often give very illuminating illustrations.