*A toile ourdie Dieu envoie le fil = God sends thread for a begun web.
Au fil de l’eau = With the stream.
Au fil de l’épée = To the edge of the sword.
Filer
Filer à l’anglaise = To leave without saying good-bye, without attracting attention; To take French leave.
*Du temps que Berthe filait = When Adam delved and Eve span; In the good old times.
[Berthe was the mother of Charlemagne. She was known as Berthe au grand pied from her club foot.]
Filer doux = To sing small.
Il faut filer (or, Filons!) (fam.) = We must be off, trot off.