For whom accumulation does not exist, who have fully understood nutriment, whose pasture is liberation in emptiness and the signless, their path is hard to trace like that of birds in the sky.

Yesaṃ sannicayo natthi — for whom accumulation does not exist: the arahant does not accumulate karma, possessions nor attachments. Their action adds nothing to the saṅkhāra (formations).

Suññato animitto ca vimokkho — liberation in emptiness and the signless: there are three liberation doors in advanced Buddhism: suññatā (emptiness), animitta (signless) and appaṇihita (wishless). The arahant dwells in these liberations as their natural territory.

Ākāseva sakuntānaṃ gati tesaṃ durannayā — their path is hard to trace like that of birds in the sky: birds in flight leave no trace. The sky keeps no record of their passage. Thus the arahant: acts without leaving karma, without inscribing their passage in the fabric of samsara.

This image of the impossible trail is one of the most evocative in Buddhism. The arahant cannot be conceptually located because there is no fixed center of identity to locate.