ખાંધી મુઠી લાખની, ઉઘાડી વા ખાય.

khāṁdhī muṭhī lākhanī, ughāḍī vā khāya.

Literally: A closed fist is worth a lakh, an open one eats air.
What it means: Keeping one's plans or wealth private is valuable; revealing them leads to loss.

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.