Bāhiya Sutta (Udana 1.10)

This beautiful verse from the sutta summarises the heart of Vipassana practice - not to attach ourselves to whatever sensation that arises from contact at any of the six sense doors and to extricate ourselves from grasping.

Then, Bāhiya, you should train yourself thus: In reference to the seen, there will be only the seen. In reference to the heard, only the heard. In reference to the sensed, only the sensed. In reference to the cognized, only the cognized. That is how you should train yourself. When for you there will be only the seen in reference to the seen, only the heard in reference to the heard, only the sensed in reference to the sensed, only the cognized in reference to the cognized, then, Bāhiya, there is no you in connection with that. When there is no you in connection with that, there is no you there. When there is no you there, you are neither here nor yonder nor between the two. This, just this, is the end of stress."