Nicene and Post-Nicene Fathers, Ser. II, Vol I:
The Church History of Eusebius.: Chapter XIX

Chapter XIX.—Domitian commands the Descendants of David to be slain.

But when this same Domitian had commanded that the descendants of David should be slain, an ancient tradition says 719 that some of the heretics brought accusation against the descendants of Jude (said to have been a brother of the Saviour according to the flesh), on the ground that they were of the lineage of David and were related to Christ himself. Hegesippus relates these facts in the following words.

Footnotes

παλαιὸς κατέχει λόγος. It is noticeable that, although Eusebius has the written authority of Hegesippus for this account, he still speaks of it as supported by “ancient tradition.” This is different from his ordinary custom, and serves to make us careful in drawing conclusions as to the nature of Eusebius’ authority for any statement from the expression used in introducing it.