A dinar belonging to a woman fell into her friend's dough without her noticing it. Asked whether she had found it she swore by the life of her husband and two children that she did not have it and in consequence they died. When the bread was broken at the meal of mourning the monej fell out.
The False Oath, the Dinar, and the Bread of Mourning
Gaster, Exempla of the Rabbis No. 121b (1924)