When Imam Ghazi bin Qais al-Andalusi (may Allah have mercy on him, d. 199 AH) reached Madinah for the purpose of seeking knowledge, he saw a man enter the Prophet's Mosque (Masjid nabawi) and sit down without praying Tahiyyat al-Masjid (the prayer of greeting the mosque). Ghazi said to him: "O brother, get up and pray two Rak'ahs. It is your ignorance that you sat down without praying Tahiyyat al-Masjid." He also said other harsh words. The man stood up and prayed two Rak'ahs. When the obligatory prayer ended, Ghazi saw that the man sat leaning back, and a circle of students began to gather around him. Now he felt quite embarrassed. He asked the people, "Who is this?" They informed him that he is Ibn Abi Dhi'b (may Allah have mercy on him), one of the jurists (Fuqaha) of Madinah and one of its great scholars. Ghazi immediately rushed to apologize to him, but the Imam said: "My brother, it matters not. You commanded us to do good, and we obeyed you."

(Al-Tamheed by Ibn Abd al-Barr: 12/460)