The Tipiṭaka in Three Languages

Tatiyavibhaṅgasutta

Suttapiṭaka · Saṁyuttanikāya · Mahāvaggasaṁyutta · Vol. 19 · Section 943

[943] And what, bhikkhus, is the faculty of joy (somanassindriya)? Whatever mental pleasure there is, bhikkhus, whatever mental comfort — the pleasant, comfortable feeling born of mind-contact (manosamphassa): this, bhikkhus, is called the faculty of joy.

English translation from the Pali (Siam Raṭṭha edition) — under review, not for citation.

This passage also appears in 2 other places