Please answer a question about the following article about Ashkenazi Jews:

In the Yoma tractate of the Babylonian Talmud the name Gomer is rendered as Germania, which elsewhere in rabbinical literature was identified with Germanikia in northwestern Syria, but later became associated with Germania. Ashkenaz is linked to Scandza/Scanzia, viewed as the cradle of Germanic tribes, as early as a 6th-century gloss to the Historia Ecclesiastica of Eusebius. In the 10th-century History of Armenia of Yovhannes Drasxanakertc'i (1.15) Ashkenaz was associated with Armenia, as it was occasionally in Jewish usage, where its denotation extended at times to Adiabene, Khazaria, Crimea and areas to the east. His contemporary Saadia Gaon identified Ashkenaz with the Saquliba or Slavic territories, and such usage covered also the lands of tribes neighboring the Slavs, and Eastern and Central Europe. In modern times, Samuel Krauss identified the Biblical "Ashkenaz" with Khazaria.

Who identified Ashkenaz with the Saquliba or Slavic territories?
Saadia Gaon