هُوَ الَّذِي أَنْزَلَ عَلَيْكَ الْكِتَابَ مِنْهُ آيَاتٌ مُحْكَمَاتٌ هُنَّ أُمُّ الْكِتَابِ وَأُخَرُ مُتَشَابِهَاتٌ
He is the One who sent the Book down to you: some of its verses are clear and foundational, and others are ambiguous. (Al 'Imran 3:7)
Umm al-Kitab indicates the foundational character of the clear verses. The ambiguous verses are also part of revelation, but they are not grounds for unsupported claims of certainty about matters beyond human comprehension.