જે પાણીએ મગ ચડે તે પાણીએ ચડાવવા.

jē pāṇīē maga caḍē tē pāṇīē caḍāvavā.

Literally: Cook them in the same water that the beans cook in.
What it means: Use the same methods that have proven successful for similar tasks.

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.