Sayyiduna Ibn Abbas (may Allah be pleased with them both) said concerning "His Kursi extends over the heavens and the earth" [Surah al-Baqarah: 255]: "It is the place of the two Feet of Allah, and the measure of His Throne cannot be estimated."
Hadith Referenceالمعجم الكبير للطبراني / باب العين / 12351