There is a sentence in the Visudhi~naan.a-kathaa by Mahasi Sayadaw.
Eva.m hi assa sallakkhentassa udarabbhantare uppajjamaana.m k?yadvaara.m pa.tiha~n~nitvaa pa.tiha~n~nitvaa uppajjamaanaa vaayo-dhaatu thambhanaakaarena vaa calanaakarena vaa pellanaakaarena vaa aavi~nchanaakaarena vaa paaka.taa hoti.：
(Mahasi Sayadaw The Progress of Insight , tr. by Nyanaponika Thera, Kandy: Bddhist Publication Society. 1985, p.50)
which Nyanaponika Thera translated as:
(While the meditator is thus engaged in noticing the element of motion which impinges continuously on the door of bodily sensitivity in the abdomen, it becomes evident to him in its aspects of stiffening, of vibrating, and of pushing and pulling.)
My question is why ‘pa.tiha~n~nitvaa’ (to be impinged) is used twice, and why ‘pa.tihantvaa’ which is active is not used instead of pa.tiha~n~nitvaa which is passive and therefore , I think, more reasonable.
Could somebody help me to understand this?
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