The Tipiṭaka in Three Languages

Ekādasakamātikā

Abhidhammapiṭaka · Dhammasaṅgaṇī · Vol. 34 · Section 532

[532] Which is that form that is the malleability of form (rūpassa mudutā)? Whatever malleability of form there is — pliancy, non-hardness, non-rigidity — this is that form that is the malleability of form.

English translation from the Pali (Siam Raṭṭha edition) — under review, not for citation.

This passage also appears in 1 other place