16.7 Sometimes the observance of such fasts extended over a considerable period of time, during which, of course, the stricter jejunium was conjoined with abstinentia (Dan.
During the exile many occasional fasts were doubtless observed by the scattered communities, in sorrowful commemoration of the various sad events which had issued in the downfall of the kingdom of Judah.
Of these, four appear to have passed into general use - the fasts of the loth, 4th, 5th and 7th months - commemorating the beginning of the siege of Jerusalem, the capture of the city, the destruction of the temple, the assassination of Gedaliah.
The last reference contains an allusion to the weekly fasts which were observed on the 2nd and 5th days of each week, in commemoration, it was said, of the ascent and descent of Moses at Sinai.
The real origin of these fasts and the date of their introduction are alike uncertain; it is manifest, however, that the observance of them was voluntary, and never made a matter of universal obligation.