Mettre la main à la pâte = To put one’s shoulder to the wheel; To set to (a special piece of) work oneself.
Les voleurs firent main basse sur tous mes effets = The thieves laid hands on all my things.
Pour cela je vous baise les mains = As for that I will not do it; “No, thank you!”
J’en mettrais la main au feu = I would swear to it; I would stake my life on it; I would take my dying oath about it.
[A reference to trial by ordeal.]
Je n’en peux mais! = I cannot help it!
[Mais is here an adverb, and shows its derivation from the Latin magis. The phrase literally means: “I can do no more.”]
Maison
Faire maison neuve (or, nette) = To change all one’s servants.