Are these quotes describing momentariness theory?
CY. Therein, when raising the foot, the material and mental phenomena which then occur do not reach the stage of bringing the foot forward. Similarly, those which occur when bringing the foot forward do not reach the stage of shifting it away; those which occur when shifting the foot away do not reach the stage of dropping it; those which occur when dropping the foot do not reach the stage of placing it on the ground; and those which occur when placing the foot on the ground do not reach the stage of pressing it against the ground.
Having come into being section by section, phase by phase, stage by stage, these phenomena break up right on the spot, popping like sesame seeds thrown onto a hot pan. Therein, who is the one that goes forward? To whom does the going forward pertain? For ultimately there is only the going of elements, the standing of elements, the sitting of elements, the lying down of elements. In each portion, together with the material form:
One state of consciousness arises,
Another state of consciousness ceases;
The process thus goes on
In uninterrupted flow like a stream.
Thus clear comprehension of non-delusion means not becoming deluded about (such actions as) going forward, etc. This concludes (the explanation of) the meaning of the phrase: “in going forward and returning, the bhikkhu acts with clear comprehension.”
Looks to me like the idea of ultimately existent phenomenon may also be present in this quote, although it’s not 100% clear to me. From DN-2 atthakatha Bhikkhu Bodhi translation here:
https://www.bps.lk/olib/bp/bp212s_Bodhi ... seship.pdf
In the same commentary:
CY. Those states of consciousness (beginning with adverting and) ending with determining which arise in the eye door, those break up together with their associated phenomena right on the spot (whether they arose). They do not see one another. Thus they are evanescent and temporary. Therein, when all the people living in a single house have died, it is not proper for the sole survivor, being subject to die that very moment, to delight in singing and dancing; in the same way, when at a single sense door the states of consciousness such as adverting, etc., along with their associated phenomena have died right on the spot (where they arose), it is not proper for the survivor—that is, impulsion—being subject to die that very moment, to delight by way of lust, hatred, and delusion.
That does sound like a useful way to develop nibbida regardless.
Maybe someone else sees a reason to not interpret this as momentariness?