ગાંઠનું ખાવું ને ગાંડા સાથે જવું (મૂર્ખાઈનાં ચિહ).

gāṁṭhanuṁ khāvuṁ nē gāṁḍā sāthē javuṁ (mūrkhāīnāṁ ciha).

Literally: Eating from one's own knot and going with a fool (signs of foolishness).
What it means: Spending your own money to support a fool's bad decisions is the height of stupidity.

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.