માણસનું ચામ, ને જુઠાનાં વચન, કશા કામનાં નહીં.

māṇasanuṁ cāma, nē juṭhānāṁ vacana, kaśā kāmanāṁ nahīṁ.

Literally: Human skin and a liar's promise are of no use.
What it means: A liar's words are completely worthless and cannot be relied upon for any purpose.

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.