It also appears that Porphyry alleged this as an instance of false ascription.

Eusebius admits that it was found in some, though not in the most accurate MSS., and Jerome says that in his day it was still the reading of 'many.' All this is very fully and fairly stated in 'Supernatural Religion' [Endnote 170:2], where it is maintained that [Greek: Haesaiou] is the original reading.

The critical question is one of great difficulty; because, though the evidence of the Fathers is naturally suspected on account of their desire to explain away the mistake, and though we can easily imagine that the correction would be made very early and would rapidly gain ground, still the very great preponderance of critical authority is hard to get over, and as a rule Eusebius seems to be trustworthy in his estimate of MSS.

Tischendorf (in his texts of 1864 and 1869) is, I believe, the only critic of late who has admitted [Greek: Haesaiou] into the text.
The false ascription may be easily paralleled; as in Mark i.

2, Matt.xxvii.9, Justin, Dial.c.Tryph.28 (where a passage of Jeremiah is quoted as Isaiah), &c.
The relation of the Clementine and of the canonical quotations to each other and to the Septuagint will be represented thus:- _Clem.