To choose an object of observation, a meditator may “investigate among various objects such as a Buddha image to see what works well”—that is, the meditator may try them out—or “read texts to see what objects of observation are recommended,” or “seek the advice of a virtuous spiritual friend, or guide (dge ba’i bshes gnyen, kalyanamitra)—a lama (bla ma, guru) who can identify a suitable object of observation”; although meditators of sharp faculties are able to choose an object of observation by studying the texts and trying out the objects of observation set forth in them, most people need to rely on a teacher.
Ge-luk-pas, however, refute the position that that any object of observation that seems easy or comfortable will do. Rather, the object of observation has to be one that will pacify the mind. Therefore, an object that arouses desire or hatred is not suitable. According to Gedün Lodrö, the erroneous position that any easy or comfortable object of observation is suitable stems from a misinterpretation of a line from Atisha’s Lamp for the Path to Enlightenment, which Gedün Lodrö interprets in the context of changing the object of observation as, “One should set one’s virtuous mind on any one object.” It can also be understood as an exaggeration of the valid position that for an inexperienced meditator, the cultivation of calm abiding is difficult and that, therefore, the object of observation should not also be difficult.
Meditators who have one of the five predominant afflictive emotions—desire, hatred, obscuration, pride, and discursiveness—must pacify the predominant afflictive emotion by using the specific object of observation that is an antidote to it; they are unable to use any other object of observation successfully until they have done so. The objects of observation that pacify the five predominant afflictive emotions are called objects of observation for purifying behavior. However, someone whose afflictive emotions are of equal strength or who has few afflictive emotions may use any of the objects of observation set forth in the Ge-luk system. Since the body of a Buddha is considered the best object of observation in this system, it would be seen as the most suitable object of observation for such a person.
—From Study and Practice of Meditation by Leah Zahler