Fòram na Gàidhlig

There's this proverb in Watson's dictionary - it's just t*ns***ed there, but I'm not certain I understand it:

'Tiugainn,' ars' an rìgh, 'Fuirich,' ars' a' ghaoth. - 'Come,' said the king, 'Stay,' said the wind.

Something like 'Man proposes, God disposes'? Or meaning specifically that however powerful a person may be, they're not omnipotent? Or am I off the target altogether?

You're on the right track.

Presumably an image from sailing - the king may decide to lead a grand expedition/raid/invasion, but if there's no wind, he's stuck.

Mòran taing dhuibh!