શિખામણ તો તેને દેખએ, જેને શિખામણ લાગે;

śikhāmaṇa tō tēnē dēkhaē, jēnē śikhāmaṇa lāgē;

Literally: Advice should be given to one who takes advice to heart.
What it means: It is useless to offer counsel to someone who will not listen.

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.