The Quran

هُوَ الَّذي أَنزَلَ عَلَيكَ الكِتابَ مِنهُ آياتٌ مُحكَماتٌ هُنَّ أُمُّ الكِتابِ وَأُخَرُ مُتَشابِهاتٌ ۖ فَأَمَّا الَّذينَ في قُلوبِهِم زَيغٌ فَيَتَّبِعونَ ما تَشابَهَ مِنهُ ابتِغاءَ الفِتنَةِ وَابتِغاءَ تَأويلِهِ ۗ وَما يَعلَمُ تَأويلَهُ إِلَّا اللَّهُ ۗ وَالرّاسِخونَ فِي العِلمِ يَقولونَ آمَنّا بِهِ كُلٌّ مِن عِندِ رَبِّنا ۗ وَما يَذَّكَّرُ إِلّا أُولُو الأَلبابِ

(Saheeh International)

It is He who has sent down to you, [O Muḥammad], the Book; in it are verses [that are] precise – they are the foundation of the Book – and others unspecific.¹ As for those in whose hearts is deviation [from truth], they will follow that of it which is unspecific, seeking discord and seeking an interpretation [suitable to them]. And no one knows its [true] interpretation except Allāh. But those firm in knowledge say, "We believe in it. All [of it] is from our Lord." And no one will be reminded except those of understanding,

Those which are stated in such a way that they are open to more than one interpretation or whose meaning is known only to Allāh, such as the opening letters of certain sūrahs.