It was narrated from Ibn Umar that the Messenger of Allah ﷺ said:
"The likeness of the Quran is that of a hobbled camel. If its owner ties its rope, he will keep it, but if he loosens its rope it will go away."

حَدَّثَنَا أَحْمَدُ بْنُ الأَزْهَرِ، حَدَّثَنَا عَبْدُ الرَّزَّاقِ، أَنْبَأَنَا مَعْمَرٌ، عَنْ أَيُّوبَ، عَنْ نَافِعٍ، عَنِ ابْنِ عُمَرَ، قَالَ قَالَ رَسُولُ اللَّهِ ﷺ " مَثَلُ الْقُرْآنِ مَثَلُ الإِبِلِ الْمُعَقَّلَةِ إِنْ تَعَاهَدَهَا صَاحِبُهَا بِعُقُلِهَا أَمْسَكَهَا عَلَيْهِ وَإِنْ أَطْلَقَ عُقُلَهَا ذَهَبَتْ " .