The gladness of the heart is the life of man, and the joyfulness of a man prolongeth his days.

[εὐφροσύνη καρδίας ζωὴ ἀνθρώπου,
καὶ ἀγαλλίαμα ἀνδρὸς μακροημέρευσις.]

The Bible (The Old Testament) (14th - 2nd C BC) Judeo-Christian sacred scripture [Tanakh, Hebrew Bible], incl. the Apocrypha (Deuterocanonicals)

Book 22b. Sirach (Ecclesiasticus) 30:22ff (Sir 30:22) [tr. KJV (1611)]
    (Source)

More on the history and acceptance of this Apocryphal book here and here.

(Source (Greek)). Alternate translations:

The joyfulness of the heart, is the life of a man, and a never failing treasure of holiness: and the joy of a man is length of life.
[tr. DRA (1899); 30:23]

Gladness of heart is life to a man,
joy is what gives him length of days.
[tr. JB (1966)]

Gladness of heart is life to anyone,
joy is what gives length of days.
[tr. NJB (1985)]

Happiness makes for a long life and makes it worth living.
[tr. GNT (1992 ed.)]

A joyful heart means life
for a human being,
and a person’s rejoicing
provides long life.
[tr. CEB (2011)]

A joyful heart is life itself,
and rejoicing lengthens one’s life span.
[tr. NRSV (2021 ed.)]