The Prophet ﷺ said, "The example of the one who knows the Quran is like the example of the owner of hobbled camels. If he keeps them tethered, he retains them, but if he lets them loose, they go away."
حدثنا يحيى عن عبيد الله أخبرني نافع
عن النبي ﷺ قال مثل صاحب القرآن مثل صاحب الإبل المعقلة إن عقلها صاحبها حبسها وإن أطلقها ذهبت
Its chain of transmission is sahih. Bukhari and Muslim both narrated it, as noted in Targheeb wal-Tarheeb 2:214. As for al-muaqqalah, it is stated in Fath al-Bari 9:70 that it is with a dammah on the meem, a fatha on the ayn, and a doubled qaf, meaning "the one tied with a hobble," which is the rope tied around a camel's knee. The reciting of the Quran and the continuation of its recitation is likened to tethering a camel that is feared to bolt. As long as the constant attention continues, the memorization remains, just as a camel remains secured as long as it is tied with its hobble. Camels in particular were singled out for mention because they are the most prone among domestic animals to bolt, and once they bolt and become able to escape, recovering them becomes difficult.