[367] When one adverts to the sign (nimitta), the mind (citta) wavers regarding the in-breath — this is an obstacle to concentration (samādhi). When one adverts to the in-breath, the mind wavers regarding the sign — this is an obstacle to concentration. When one adverts to the sign, the mind wavers regarding the out-breath — this is an obstacle to concentration. When one adverts to the out-breath, the mind wavers regarding the sign — this is an obstacle to concentration. When one adverts to the in-breath, the mind wavers regarding the out-breath — this is an obstacle to concentration. When one adverts to the out-breath, the mind wavers regarding the in-breath — this is an obstacle to concentration.
For one adverting to the sign, the mind is distracted regarding the in-breath;
for one adverting to the in-breath, the mind wavers regarding the sign;
for one adverting to the sign, the mind is distracted regarding the out-breath;
for one adverting to the out-breath, the mind wavers regarding the sign;
for one adverting to the in-breath, the mind is distracted regarding the out-breath;
for one adverting to the out-breath, the mind wavers regarding the in-breath.
These are the six mental defilements (upakkilesa) of concentration through mindfulness of breathing (ānāpānasati);
if the mind of one who wavers because of them is not liberated,
then, not understanding liberation (vimokkha), such persons become dependent on the word of others.
A mind running after the past, fallen into distraction, is an obstacle to concentration. A mind longing for the future, set wavering, is an obstacle to concentration. A slack mind, fallen into laziness, is an obstacle to concentration. An over-exerted mind, fallen into restlessness (uddhacca), is an obstacle to concentration. A mind that cognizes excessively, fallen into lust, is an obstacle to concentration. A mind that fails to cognize, fallen into ill will (byāpāda), is an obstacle to concentration.
English translation from the Pali (Siam Raṭṭha edition) — under review, not for citation.