Gemara: Rav Yehuda was sitting before Shmuel. A woman came in and screamed about her plight, and Shmuel did not take heed of her. Rav Yehuda said to him: Do you not agree with the pasuk, "One who seals his ear from hearing the cry of the poor will also call out and not be answered" (Mishlei 21:13)? Shmuel answered: Sharp one, your leader (Shmuel was Rav Yehuda’s teacher) will be exposed to cold water; the leader of your leader (Mar Ukva) will be exposed to hot water. After all, Mar Ukva is the head of the rabbinical court, as it says: "The house of David – thus said Hashem: Rule in the mornings rulings of justice and save the victim of robbery from he who is oppressing him" (Yirmiya 21:12).

Ein Ayah: The very feeling of compassion and agitation upon seeing one who is oppressed, causing one to come to his aid when he is not obligated to do so and when it is the job of others, is intrinsically a wonderful characteristic. The moral expression of this good emotion – to care about the pain of the distressed – is at times more important than the value of the action taken.
Therefore, one should not close the doors of his heart to the good and sensitive emotions that are aroused in every heart of flesh to have mercy and to empathize with the oppressed and to help protect them from their oppressors. One who seals his ear from the cry of the poor causes the good emotion of compassion for those in distress to retreat. This swallows up the G-d-given gift of proper emotion that is found in the midst of the human heart. It is actually the foundation of the purpose of prayer, to arouse the proper emotions to act positively on the heart, as the spirit is elevated optimally when one serves Hashem through the service of the heart (prayer).
When one acts in his lifestyle in a manner that opposes fine emotion and seals off the cry of the poor, he causes a situation in which there is not benefit from prayer. Then he will not be awarded the special spiritual effectiveness of a proper prayer, which makes it more likely to be heard and fulfilled. Usually, the apparatus of needs that make prayer necessary line up with the emotional needs that people have, each according to its value. Then the fulfillment of the prayer will bring an emotional divinely recognized benefit. However, this is lost when one has lost his emotional sensitivity to have compassion for the distressed. Then, there is not a divinely recognized benefit achieved by fulfilling his needs. He will need a more daunting situation than one provided by normal prayer before his needs will be addressed.
However, there are times when there is a broad, lofty need to allow one’s intellect to ignore the good emotion of compassion. In those cases, the cold calculated mind has an advantage over emotion. One such situation is when it is important that there be a communal legal hierarchy, where there is a central address for legal complaints. This is especially important when the chief judge is from the House of David, as the centrality of the dynastic family leads to the greatness of Israel. Then people will have a healthy desire for the restoration of the kingdom of Israel. This is enough justification for others to not get involved in rushing to the aid of the oppressed. That is what Shmuel alluded to in regard to Mar Ukva (a leading judge and a member of the family of David). He was the one who had full responsibility and would be punished if he did not take steps. When successful, the personal and national seeds could unite in the actions of such an important person as Mar Ukva.