Reference for Taanit 30:15
(כל אחד ואחד (נוטל ונותן) בראשו אמר רב אדא) וכל אחד ואחד (נוטל ונותן) בראשו נשיא ואב בית דין נמי נשקלו אינהו ונינחו בראשייהו מאי שנא דשקיל איניש אחרינא ומנח להו אמר רבי אבא דמן קסרי אינו דומה מתבייש מעצמו
WE DO NOT ORDAIN UPON THE COMMUNITY A FAST ON NEW MOON, ON HANUKKAH, OR ON PURIM, BUT IF THEY HAD ALREADY BEGUN [A SERIES OF FASTS AND ONE OF THESE FESTIVE DAYS INTERVENED] THEY DO NOT INTERRUPT [THEIR FASTS]; THIS IS THE OPINION OF RABBAN GAMALIEL. R'MEIR SAID: EVEN THOUGH R'GAMALIEL IS OF THE OPINION THAT THE [FASTS] SHOULD NOT BE INTERRUPTED HE YET AGREES THAT THEY SHOULD NOT COMPLETE THEIR FASTS. AND THE SAME APPLIES TO THE NINTH OF AB SHOULD IT FALL ON A FRIDAY. <big><b>GEMARA: </b></big>WHAT IS THE ORDER [OF SERVICES] FOR FAST DAYS? THE ARK IS TAKEN out etc. Does all this apply to the first six fasts? If so, is there not a contradiction raised against this? [For it has been taught]: On the first three and also on the second three [fasts] they enter the synagogue and pray there in the same way as they pray all the year round, but on the last seven the Ark is taken to the open space of the city and ashes are placed on the Ark and also upon the head of the Ab-Beth-din, and everyone else puts ashes upon his own head. R'Nathan says: They take wood-ashes!<span class="x" onmousemove="('comment',' [MS.M. omits: 'and also upon the head... wood ashes', these words being unnecessary in this connection.]');"><sup>13</sup></span> - R'Papa replied: Our Mishnah also refers to the last seven fasts. ANd ON The HEAD OF THE NASI: And afterwards [the Mishnah] states, EVERYONE ELSE PUTS ASHES UPON HIS OWN HEAD. But is it so? Has it not been taught: Rabbi says: Where it is a case of doing honour we begin at the most distinguished, but where it is a case of censuring we begin at the least important; as it is said, And Moses said unto Aaron, and unto Eleazar and unto Ithamar;<span class="x" onmousemove="('comment',' Lev. X, 6. (3) [The brackets appear also in the original; these words being apparently superfluous, they are omitted in MS.M.]');"><sup>14</sup></span> but where it is a case of censuring we begin at the least important, (for a Master said:) First the serpent was cursed, and afterwards Eve and [only] then Adam? -Here [in our Mishnah] it is also a case of doing honour, because [by this act] the people convey to them<span class="x" onmousemove="('comment',' To the Nasi and Ab-Beth-din.');"><sup>15</sup></span> [the thought] you are worthy to entreat for mercy on behalf of us all. EVERYONE ELSE PUTS ASHES ON HIS OWN HEAD: R'Adda said: Seeing that everyone else puts the ashes on his own head let also the Nasi and the Ab-Beth-din themselves take ashes and place them on their own heads! Why should someone else take ashes and put them on their head? - R'Aba of Caesarea replied: To humiliate oneself is not the same as being humiliated by others.