Literal Translation
Good blood!
Actual Meaning
Damn it!
Etymology
Originally, there was the swear word ‘par le sang (de) Dieu!’ (by God’s blood!), which was used in the 14th century.
But one can imagine that in certain periods, such as the Ancien Régime (from the 15th to the 18th century), for example, when the nobility and the clergy were all-powerful, such a swear word was blasphemous. Palsambleu is therefore a “politically correct” distortion of this swear word, a version of which, ‘par le sanc bieu’, can be found as early as 1402. Molière used ‘par le sang bleu’ and ‘par la sangbleu’.
‘Bon sang!’ is in the same vein. In fact, ‘bon sang de bon dieu’ is a more recent equivalent (19th century) of ‘par le sang de Dieu’. In its shortened form, it gave rise to one of our expressions which, when lengthened, gave rise to the variants ‘bon sang de bois’ or ‘bon sang de bonsoir’.