“Has he attained knowledge of the Unseen?” This is an interrogative. Meaning: Did he know what is in it? That is, he has not attained it. “Or has he taken a pledge from the Most Merciful?” Meaning: He has not done so. The pledge is monotheism, according to the interpretation of some.
﴿أطلع الْغَيْب﴾ عَلَى الِاسْتِفْهَامِ؛ أَيْ: عَلِمَ مَا فِيهِ؛ أَيْ: لَمْ يَطَّلِعْ ﴿أَمِ اتخذ عِنْد الرَّحْمَن عهدا﴾ أَيْ: لَمْ يَفْعَلْ، وَالْعَهْدُ: التَّوْحِيدُ؛ فِي تَفْسِير بَعضهم.