mikenz66 wrote:Seems the same as the Satipatthana Sutta, but without the detailed explanation of the various mental qualities (dhammas).
The Satipatthanasamyutta of the Samyutta Nikaya (47.*) offers... a less agglutinative approach to satipatthana, which I feel allows for a very detailed approach. For example, SN 47.40 distinguishes the establishment of mindfulness (which includes the red text you've referenced) from the development of mindfulness; this last is "satipatthanabhavana", and involves "contemplating the nature of origination...", "...vanishing...", and "...origination & vanishing..." in the four categories.
Here, and in the quote you provide, watching closely with equanimity is to see with discernment the abandoning of greed & distress (BB: covetousness & displeasure). This use of equanimity is brought up again at SN 54.10, in the Anapanasatisamyutta. This is a clear instruction, and numerous subtleties such as these are explicated throughout the many Suttas in these sections of the Samyutta.
Given the potential expansiveness of these topics, I want to stay closely focused within the domain of the OP, to wit: there is no "two truths" description given anywhere throughout these sections, even though the Buddha is careful to make distinctions such as satipatthana/satipatthanabhavana, or anapanasati/anapanasatisamadhi. At no point does a "two truths" description seem to clarify any aspect of these practices, and therefore I think the interpolation is unwarranted and unhelpful, perhaps even obfuscatory.
What does holding a two truths notion actually help you to understand?