વહુના વાકની ને વેપારીના આંકની ખબર પડે નહીં.

vahunā vākanī nē vēpārīnā āṁkanī khabara paḍē nahīṁ.

Literally: No one knows the fault of a daughter-in-law or the calculation of a merchant.
What it means: Said because the misdeeds of a daughter-in-law inside a home and the accounting tricks of a merchant remain hidden from outsiders.

Also said as

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.