Midrash su Geremia 49:6

(Fol. 27b) We are taught that R. Eliezer says: "He who prays behind his teacher, he who greets his teacher [without calling him Rabbi], he who opposes his teacher's school [by organizing a separate academy], and who makes statements [in his teacher's name] that he did not hear from his teacher, causes the departure of the Shechinah from Israel." Our Rabbis taught: That once a disciple appeared before R. Joshua and said to him: "Rabbi, is the evening service optional or obligatory?" "Optional," answered R. Joshua. He then came before Rabban Gamaliel and asked the same question: "Is the evening service optional or obligatory?" "Obligatory," was Rabban Gamaliel's answer. "Behold! R. Joshua said to me it is optional!" the disciple remarked. Whereupon Rabban Gamaliel replied, "Wait until the shield bearers (great scholars) enter the house of learning." As soon as the shield bearers entered the house of learning, the inquirer arose and asked, "Is the evening service optional or obligatory?" "Obligatory," responded Rabban Gamaliel. "Is there any one here differing with me on this subject?" inquired Rabban Gamaliel of the scholars. "No," came the answer from R. Joshua. "Behold," interrupted Rabban Gamaliel, "it is said in your name that the service is only optional. Arise Joshua! And let the witness testify against thee!" R. Joshua stood up and said: "Were I alive and he (the witness) dead, I would have been able to deny it, but now, when I am alive and he is alive, how can one living being deny another living being?" So Rabban Gamaliel continued his lecture while R. Josliua remained standing, until all the people moved in excitement and said to Chutzephith the Meturgeman, "Stop!" and he stopped. "How long," said they, "shall we permit R. Joshua to be afflicted and reproached? Last New Year Rabban Gamaliel afflicted and reproached him. In Bechoroth, in the incident of R. Zadok, Rabban Gamaliel annoyed him and now again he reproached and afflicted him; shall we allow such annoyance to be continued? Let us take steps to deprive him of his dignity (of being the Exilareh). But who shall be his successor? Shall we put up R. Joshua? He is his chief opponent [and it would cause him too much aggravation]. Shall we put up R. Akiba? He has no ancestral merits, and may be disposed to Heavenly punishment [through prayers]. Let us therefore choose R. Elazar b. Azaria for he is wise, rich, and the tenth descendant of Ezra. He is wise, and therefore will be able to answer when questioned; he is rich and therefore, if ordered to attend the Emperor's court [of Rome], he will be as well able to do so as Rabban Gamaliel; he is the tenth descendant of Ezra and has therefore ancestral merits, and he (Rabban Gamaliel) will not be able to afflict upon him Heavenly punishment." So they came [to R. Elazar b. Azarlia] and said to him: "Is the master willing to become the head of the Academy?" (Fol. 28a.) R. Elazar replied: "I'll go and consult my household." He went and consulted his wife. "Perhaps," said she to him, "they will also depose thee [and you will be disgraced]." "There is a maxim," replied he. "'Use thy precious bowl while thou hast it. even if it be broken the next day.'" "But," said she, "thou hast not any gray hair [and they will not respect thee]." At that time he was but eighteen years of age; thereupon miraculously eighteen of his locks suddenly turned gray. And this R. Elazar b. Azaria meant when he said: "Behold! I am as a man of seventy years of age" but not aged seventy. We are taught that on that day the porter was removed from the door [of the academy], and admission was granted to all students, for, during the administration of Rabban Gamaliel, the announcement was made: "Every scholar whose interior is not like his exterior (who is not pious), shall not enter the academy." On that day many benches were added in the academy. R. Jochanan said: "There is a difference of opinion between Abba Joseph b. Dustoi and the Rabbis; according to one, four hundred benches were added and according to the other, seven hundred benches [were added]." When Rabban Gamaliel noticed the tremendous increase he became discouraged and said to himself, "God forbid, I have perhaps prevented so many from studying the Torah." In a dream was shown to him "white earthen pitchers filled with ashes." But this was shown to him only in order to calm him. We are taught: "On that day the treatise of Edioth was studied in the academy and wherever we find 'On that day,' it means the day on which R. Elazar b. Azaria became the head of the academy. There was no Halacha previously undecided in the academy which was not decided that day. Even Rabban Gamaliel himself, although deposed, did not refrain from attending the academy, as is shown from what we are taught (in a Mishnah): 'On that day Juda the Ammouite, a proselyte, appeared in the academy and asked: 'May I enter the congregation [to marry a Jewess]?' Rabban Gamaliel said unto him: 'Thou art not at liberty to do so,' but R. Joshua said, 'Thou art at liberty to do so.' Rabban Gamaliel then said to R. Joshua, 'Behold it is said (Deu. 23, 4.) An Ammonite ' or Moabite shall not enter the congregation of the Lord!" To this R. Joshua retorted and said, 'Are then these nations still in their native places? Did not Senacherib, the king of Assyria, transplant the nations? As it is said (Is. 10, 13.) I have removed the bounds of the people, and their laid-up treasures have I plundered, etc., therefore, not knowing, we go according to the majority [and the majority are not Ammonites].' 'But,' replied Rabban Gamaliel, 'behold, it is said (Jer. 49, 6.) And afterwards I will bring again the captivity of the children of Ammon, so they must have already returned.' To which R. Joshua rejoined: "Behold it is also said (Amos 9, 14.) And I will bring again the captivity of my people Israel, and these have not returned as yet.' Thereupon the proselyte was immediately permitted to enter the congregation." Then Rabban Gamaliel said to himself: "Since it is so [that R. Joshua's decision was carried], I shall now go and effect a reconciliation with R. Joshua." He thereupon went. When he reached R. Joshua's house, he noticed that the walls of the house were black. "From the appearance of the walls of thy house," said Rabban Gamaliel, "it is evident that you are a smith." R. Joshua replied: "Woe unto the age whose leader thou art! for thou knowest not of the cares with which the scholars are occupied and whence they derive their livelihood!" "I have reproached thee, forgive me," Rabban Gamaliel pleaded, but R. Joshua ignored him. "Do it," he again pleaded, "for the sake of the honor of my father's house." R. Joshua then accepted his apology. "Now," they said, "who will go and inform the Rabbis?" [that they had become reconciled.] "I shall go," said a certain laundryman who was there. So R. Joshua sent the following message [through him]: "He who wore the vestment, shall be dressed with it again, and he who has not worn the vestment shall say to him who wore it: 'Take ofT thy priestly cloth, and I shall put it on.'" As soon as R. Akiba was informed of the situation, he said to the Rabbis: "Let all gates [leading to the academy] be closed so that none of Rabban Gamaliel's subordinates shall come and afflict the Rabbis" [in a spirit of revenge for their stand against Rabban Gamaliel]. Meantime R. Joshua said to himself: "It will be much better that I myself shall go and inform them." Accordingly he went and [upon reaching the academy] rapped at the door saying: "Let him sprinkle who is a sprinkler, the son of a sprinkler (a scholar, the son of a scholar); he who is neither himself a sprinkler, nor the son of a sprinkler shall say to him who is a sprinkler and the son of a sprinkler Thy water is plain cave water and thy ashes are plain ashes of a burned cane."