સુભાનઅલ્લા; છોટે ભાઈ સો છોટે ભાઈ, બડે ભાઈ તો સુભાનઅલ્લા.

subhānaallā; chōṭē bhāī sō chōṭē bhāī, baḍē bhāī tō subhānaallā.

Literally: Praise be to God; the younger brother is indeed the younger brother, but the elder brother is 'Praise be to God!'
What it means: Said when the elder sibling or partner is even more extreme, foolish, or remarkable than the younger one.

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.