The Perfection of Wisdom - How panna is to be developed

Some people wonder how, in the development of satipatthana, one can at the moment of seeing understand the characteristics of the realities that are appearing. There is only one way: when someone has listened to the Dhamma he can be mindful so that he will understand the characteristic of seeing that sees at this very moment, or the characteristics of the other dhammas that are appearing at this moment.
At the moment of understanding realities, satipatthana is being developed. Sati is mindful of the characteristic of the reality which experiences or knows, such as seeing, and panna is able to understand that characteristic, it realizes that it is only a reality which is not self, not a being, not a person.
At whatever moment seeing, hearing, the other sense-cognitions or other types of citta present themselves, the ayatanas can be understood: the eye and visible object, the ear and sound, the other sense-bases and sense objects, citta and dhammas. At those moments panna begins to develop by knowing the characteristics of realities which are appearing. We can use the word satipatthana for this process, but what matters above all is knowing how panna is to be developed: when seeing appears, one begins to understand the characteristic of seeing, when hearing appears, one begins to understand the characteristic of hearing, and so on for the other sense-cognitions and for other types of citta. The perfection of energy, viriya, should arise together with panna, otherwise one will make an effort for something else, different from the right effort to understand the characteristics of realities, just as they naturally arise in daily life.