સિંહ ગમન, પુરુષ વચન, કેળ ફળે એક વાર;

siṁha gamana, puruṣa vacana, kēḷa phaḷē ēka vāra;

Literally: A lion's march, a true man's word, and a banana tree bear fruit only once.
What it means: Honorable people stand by their word and never go back on it, just as certain natural events happen only once.

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.