When a man wished to accompany Sayyiduna Ibn Umar (may Allah be pleased with them both) on a journey, he would set him the condition that he not accompany him riding a camel that eats filth (jallalah), that he not dispute with us over the call to prayer (adhan), and that he not fast without our permission.
Hadith Referenceالمعجم الكبير للطبراني / باب العين / 12996