પાદવાની પ્રાપ્તિ નહીં, ને ગેલંદાજ થવું.

pādavānī prāpti nahīṁ, nē gēlaṁdāja thavuṁ.

Literally: Having no ability to pass wind, yet pretending to be a cannoneer.
What it means: Ridiculous boasting by someone who lacks even the most basic capabilities.

Also said as

ગુજરાતી કહેવતસંગ્રહ (Gujarati Kahevat Sangrah) (1923) · 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.