તેલી તેલમાં લીન, તંબોલી પાનમાં પ્રવીણ.

tēlī tēlamāṁ līna, taṁbōlī pānamāṁ pravīṇa.

Literally: The oil-presser is absorbed in oil, the betel-seller is expert in betel leaves.
What it means: Every professional excels in and remains dedicated to their own trade.

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.