[275] An external phenomenon (dhamma) is a condition for an external phenomenon by root condition (hetu-paccaya): external roots are a condition, by root condition, for the associated aggregates and for mind-originated forms (cittasamuṭṭhāna-rūpa). At the moment of rebirth-linking (paṭisandhi), external roots are a condition, by root condition, for the associated aggregates and for external kamma-born forms (kaṭattārūpa).
An external phenomenon is a condition for an internal phenomenon by root condition: external roots are a condition, by root condition, for the mind (citta). At the moment of rebirth-linking, external roots are a condition, by root condition, for the mind and for internal kamma-born forms.
An external phenomenon is a condition for an internal phenomenon and for an external phenomenon by root condition: external roots are a condition, by root condition, for the associated aggregates, for the mind, and for mind-originated forms. At the moment of rebirth-linking, external roots are a condition, by root condition, for the associated aggregates, for the mind, and for internal and external kamma-born forms.
English translation from the Pali (Siam Raṭṭha edition) — under review, not for citation.