It once happened that the elders descended from Jerusalem to their cities and decreed a fast because windblast the size of an oven's mouth was seen [on grain] in Ashkelon. They further decreed a fast because wolves had devoured two children beyond the Jordan [River]. R' Yose says: [The fast was decreed] not because they had devoured [the children], but [merely] because they were seen [in the city during the day].