Ekādasakamātikā

Abhidhammapiṭaka · Dhammasaṅgaṇī · Vol. 34 · Section 536

[536] Which is that form which is the decay of form (rūpassa jaratā)? That which is the aging (jarā) of form (rūpa) — the agedness, brokenness of teeth, grayness of hair, wrinkledness of skin, the decline of the life span, the ripening of the faculties (indriya)… — this is that form which is the decay of form.

English translation from the Pali (Siam Raṭṭha edition) — under review, not for citation.

This passage also appears in 1 other place

Vol. 34 · Section 585 — Ekādasakamātikā