A variety of Anuprekṣā (4) (contemplative meditation) of Śukladhyāna (pure meditation);
reflecting upon the inauspicious nature of the objects (of wordly existence).
'asubhe' tti aśubhatvaṃ saṃsārasyeti gamyate. dhī saṃsāro jaṃmi juyāṇao paramarūvavavviyao. mariūṇa jāyai kimī tattheva kaḍevare niyae...
(Sthā 4.72 Vṛ Pa 181)