Imam Ahmad Ibn Hanbal, may Allah ﷻ be pleased with him, was once traveling and needed to stay somewhere overnight. When he went to the mosque, the guard (not recognizing Imam Ahmed) denied him entrance. Imam Ahmed insisted on his right, yet he was refused. Frustrated, Imam Ahmed resolved to spend the night on the mosque’s front porch/yard. The guard became furious and dragged him away, despite his old age and frailty.
A baker, whose shop was nearby, watched this scene and took pity on Ibn Hanbal and offered the great scholar food and a place to sleep. He watched as the baker mixed and kneaded the dough, tended the fire, and pulled hot loves from the oven, all the while uttering remembrances of Allah and istighfar (asking for Allah’s forgiveness). Finally, Ibn Hanbal asked the pious baker what inspired him so. The baker responded it had become like second nature saying he did as he did in thanks to Allah who had answered all his prayers. All save one.
When Ibn Hanbal asked what that unanswered prayer was, the baker responded: “To see the famed Imam Ahmad ibn Hanbal.” At this, tears came to Ibn Hanbal’s eyes and he told the baker, “I am Ahmed ibn Hanbal!”. He then went on to add, “By Allah! I was thrown from the mosque to meet you.”
Disclaimer: Unfortunately, I do not have the exact reference of the story being narrated above but apparently it is narrated by Imam ibn al-Jawzi in a book he wrote about the virtues of Imam Ahmad.