Rub a dub dub thanks for the grub意思

"Rub a dub dub, thanks for the grub" is a playful and colloquial way of saying "Thank you for the food." The phrase is a playful take on the traditional English nursery rhyme "Rub-a-dub-dub" which goes:

Rub-a-dub-dub, Three men in a tub, And who do you think they be? The butcher, The baker, The candlestick-maker, Turning over a tub with me.

The phrase "thanks for the grub" is a casual way of expressing gratitude for the food provided, often used in a friendly or humorous context. "Grub" is a slang term for food, especially in a casual or rustic setting.