દૂધ પાઈને સાપ ઉછેરવા.

dūdha pāīnē sāpa uchēravā.

Literally: To rear a snake by feeding it milk.
What it means: Nurturing or helping someone who will eventually turn around and harm you.

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.