All perfect praise be to Allah, The Lord of the Worlds. I testify that there is none worthy of worship except Allah, and that Muhammad is His slave and Messenger. {C}
The interpretation of the Salaf (righteous predecessors) of the meaning of the word Istiwaa’ is an explanation of its literal meaning, and this does not need a chain of narrators to the Prophet because the Quran was revealed in the Arabic language and the Arabs interpreted it according to this language.
An example of this, if someone says that the word جاء ‘came’ in the saying of Allah (which means): {And there came from the farthest end of the city a man, running.} [Quran 36:20]; means arrived, showed up, and to be at a place, then he is not demanded to provide a chain of narration to the Prophet to prove this interpretation because this is an Arabic word and this is its meaning in the Arabic language.
The same thing applies to the word Istawa; the scholars of the Salaf interpreted it with other Arabic words just as a means of clarifying the meaning of the word in the Arabic language according to its context.
Saheeh Al-Bukhaari reads:
"Abul-‘Aaliyah said: {He directed Himself (Istawa) to the heaven} [Quran 2:29] meaning ‘He elevated’; {and made them (sawwaahun)} [Quran 2:29], meaning He created them. Mujaahid said: {He directed Himself (Istawa) to}, means rose above {the Throne} [Quran 7:54]” [End of quote]
On the other hand, Abul-‘Aaliyah was a student of many of the companions . He was alive during the time of the Prophet when he was a young man, and embraced Islam during the caliphate of Abu Bakr and used to enter upon him (to learn from him). He heard from ‘Umar, ‘Ali, Ubayy, Abu Tharr, Ibn Mas’ood, ‘Aa’ishah, Abu Moosa, Abu Ayyoob, Ibn ‘Abbaas, Zayd ibn Thaabit, and several other Companions. He memorized the Quran and recited it to: Ubay ibn Ka'b, and he was prominent in teaching knowledge, and he became famous (for his knowledge).
He learned the recitation (of the Quran) by listening it directly from ‘Ubayy, Zayd, and Ibn ‘Abbaas. So, his Tafseer is a Tafseer of an Arab scholar who was fluent in Arabic language who knows very well the statements of the Companions regarding Tafseer.
Mujaahid was like him, as he was a student of Ibn ‘Abbaas . Ath-Thahabi said about him in his book As-Siyar:
"He (Mujaahid) narrated so many narrations from Ibn ‘Abbaas, and he did well. He learned the Quran from him as well as the Tafseer (interpretation of the Quran) and Fiqh (Islamic Jurisprudence). He also learned from Abu Hurayrah, ‘Aa’ishah, Sa’d ibn Abu Waqqaas, ‘Abdullaah ibn ‘Amr, Ibn ‘Umar, Raafi’ ibn Khadeej, Umm Kurz, Jaabir ibn ‘Abdullaah, Abu Sa’eed Al-Khudri, Umm Haani’, Usyad ibn Thaheer, and many others.” [End of quote]
Therefore, there is no room for doubting their interpretation of the word Istiwaa’.
For more benefit, please refer to Fataawa 277453, 326068 and 85919.
Allah knows best.