Among the unique laws that apply to a king and a kohen gadol are rules regarding their haircuts. Our Gemara quotes a baraita that teaches that a king must have his hair cut on a daily basis, while the kohen gadol would get his hair cut once a week. The source for the king’s special grooming stems from the Gemara’s interpretation of the passage in Sefer Yeshayahu (33:17) that states that a king should be seen in his beauty; the kohen gadol needs to prepare himself for the new group of priests that come to work in the Temple.
Some of the rules regarding the proper deportment of the kohen gadol have their source in Chapter 44 in Sefer Yeḥezkel where the prophet lists what the kohen can and cannot do. In pasuk 20 , for example, the navi says regarding a kohen that kasom yiksemu et rashekhem – that he must keep the hair on his head trimmed. Our Gemara asks how that statement should be understood, and we are told that he has a tisporet lulyanit – a unique haircut – which is explained by Rav Ashi to mean that the tip of one hair reached the root of the next one. Rabbi [Yehuda HaNasi] pointed to his son-in-law, Ben Elasa, as someone who spent significant sums of money on his haircut, and said that he did it for the sole purpose of showing off the haircut of the kohen gadol.
We have little information on Ben Elasa from Talmudic sources, although it appears that he was a wealthy person and not a scholar. It appears that there was tension between him and the students, and Rabbi’s statement about his haircut is an example of Rabbi’s attempts to defuse that tension.
The description of the haircut is not very clear. From the Rambam it appears that all of the hairs were cut to a short, uniform height. The Ra’avad appears to suggest that the hair was set up in a series of curls that were cut in such a way as to allow the tip of one to reach the root of the next one.