માણસનું ચામ, ને જુઠાંનાં વચન, કશા કામનાં નહીં.

māṇasanuṁ cāma, nē juṭhāṁnāṁ vacana, kaśā kāmanāṁ nahīṁ.

Literally: Human skin and a liar's promises are of no use whatsoever.
What it means: The commitments of a dishonest person carry no practical worth.

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.