إِنَّا لَمَّا طَغَى الْمَاءُ حَمَلْنَاكُمْ فِي الْجَارِيَةِ
When the water exceeded its bounds, We carried you in the vessel.
Ṭughyān literally evokes excessive transgression or rebellion. The term is used for the water's extraordinary abundance and rise, casting a perceptible flood in the language of transgression.
Source: arrogant transgression or overstepping, a conceptual meaning.
Target: the visible excess of water.
Common feature: exceeding an established limit, understood conceptually.