A daimen icker in a thrave 'S a sma' request;I'll get a blessin wi' the lave, An' never miss't! (15-18)
The speaker says that, after all, he can afford to lose the occasional ear of corn (a "daimen icker") out of a big bundle of 24 (a "thrave"). It isn't much for the mouse to ask. And if the speaker lets it go without complaint, he'll have a blessing on the remainder. This could be a not-so-subtle nudge to the reader to think about helping out poor people. If the speaker—a poor farmer in Scotland—can give grain to a mouse out of charity and sympathy, can't the wealthy reader give something to help poor people make it through the winter? After all, the remainder of your wealth will be blest by helping the poor.
Thy wee bit housie, too, in ruin! (19)
After the speaker's subtle connection of the mouse's situation with the condition of poor people everywhere, his description of the mouse's "house," instead of her nest, seems all the more appropriate. It's easy to forget that it's a mouse, and not a human, that we're talking about here.