Padīpopamasutta

sn54.8:13.1 Now, a mendicant might wish:

sn54.8:13.2 ‘With the fading away of rapture, may I enter and remain in the third absorption, where I will meditate with equanimity, mindful and aware, experiencing for themselves the bliss of which the noble ones declare, “Equanimous and mindful, one meditates in bliss.”’

sn54.8:13.3 So let them closely focus on this immersion due to mindfulness of breathing.