Ibn Ishaq
Waqidi will always give precise dates, locations, names, where Ibn Ishaq has none, accounts of what triggered the expedition, miscellaneous information to lend color to the event ... But given that this information was all unknown to Ibn Ishaq, its value is doubtful in the extreme. And if spurious information accumulated at this rate in the two generations between Ibn Ishaq and al-Waqidi, it is hard to avoid the conclusion that even more must have accumulated in the three generations between the Prophet and Ibn Ishaq.