Doubt about the fact that insight wholesomeness consists of simply observing the presently arising mental and physical phenomena is also skeptical do… - Mahasi Sayadaw

One who fails to observe mental and physical phenomena every time they arise cannot see them as merely mental and physical phenomena. Furthermore, one does not realize their causality, impermanence, unsatisfactoriness, notself, or their immediate disappearance upon arising and their continuous disappearance thereafter. Therefore, one mistakenly identifies these mental and physical phenomena with a personal entity, a person who is either born without any cause or created by a creator. One mistakes them for someone or something permanent and pleasant, everlasting, and unchanging.

The insight process flows smoothly if sensual desires do not arise. If they do arise, however, they obstruct the flow of insight. They appear as rivals to insight, as if saying, "It is our turn; stay away insight!"

When intensively practicing insight, your first priority should be given to it, with the understanding that insight is the essential cause of liberation. ... You should not interrupt it for a minute or even a second.