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

It was narrated from Ibn Umar that the Messenger of Allah(PBUH) 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." Translation Not Available

Book Ref: Sunan Ibn Majah Book 33 Hadith 3783
Web Ref:  Sunan Ibn Majah Vol 5 Book 33 Hadith 3783