In the name of Allah, the Compassionate, the Merciful
Imam Malik one day entered the Masjid after Asr. Towards the front of Masjid An-Nabawee he drew closer and sat down. Rasul Allah had commanded that anyone who enters the Masjid should not sit until he first prays 2 rakas as a salutation of the Masjid. Imam Malik was of the opinion however that Rasul Allahs forbiddance of praying after Asr took precedence and so he would teach his students to not pray the tahiyyatul Masjid if they entered between the Asr and Maghrib time.
At that moment that Imam Malik sat down, a young boy had seen him sit without first praying the 2 raka's of Tahiyyatul Masjid. The young boy scorned him, "Get up and pray 2 rakas!"
Imam Malik dutifully stood up once again and began praying the 2 rakas. The students sat stunned: What was going on? Had Imam Malik's opinion changed?
After he had completed the salah, the students swarmed around and questioned his actions.
Imam Malik said, "My opinion has not changed, nor have I gone back on what I taught you earlier. I merely feared that had I not prayed the 2 rakas as the young boy commanded, Allah may include me in the Ayah...
[And when it is said to them, 'Bow (in prayer)', they do not bow.]
- al mursalat 77/48.
Imam Ahmad held the opinion that eating camel meat nullifies ones Wudu, an opinion that the majority of scholars differed from. Some students asked him, "If you find an Imam eating camel meat in front of you and - without first making Wudu - then leads the Salah, would you pray behind him?" Imam Ahmad replied, "Do you think I would not pray behind the likes of Imam Malik...