Contemplation qua falling off of Karma- The ninth Anuprekṣā (4) (contemplative meditation); repeated reflection or exercise (i.e. practice) of contemplation on Nirjarā (1) (falling off of Karma) resulting from Tapa (austerity) and endurance of Pariṣahas (hardships) of ascetic life.
nirjarāvedanāvipāka ityanarthāntaram. sa dvividho'buddhipūi'vaḥ kuśalamūlaśca......tam gunato'nucintayetśubhānubandho niranubandho veti, evamanucintayankarmanirjaraṇāyaivaghatata iti nirjarānuprekṣā.
(TaBhā 9.7)
See - Abuddhipūrvī Nirjarā. Kuśalamūlā Nirjara.