Trung Bộ Kinh (Majjhima Nikaya) 3:101
SUJATO‘nirodhānupassī assasissāmī’ti sikkhati, ‘nirodhānupassī passasissāmī’ti sikkhati;
or observing cessation,
‘nirodhānupassī assasissāmī’ti sikkhati, ‘nirodhānupassī passasissāmī’ti sikkhati;
or observing cessation,