કૌતુક વગર હસવું હોય નહીં.

kautuka vagara hasavuṁ hōya nahīṁ.

Literally: There is no laughter without a cause.
What it means: Every event has an underlying reason or origin.
The English proverb Shah set beside it: Necessity knows no law.Need makes the old wife trot.No effect without cause.

Also said as

ગુજરાતી કહેવતસંગ્રહ (Gujarati Kahevat Sangrah) (1923) ગુજરાતી કહેવતસંગ્રહ (Gujarati Kahevat Sangrah) (1921) · read from the scan by machine — the Gujarati itself is unchecked · English is machine-made and nobody has checked it yet

Heard it differently, or know we've got the sense wrong? Tell us — that is exactly the kind of correction this needs.