“Haman took the garments and the horse.” (Esther 6:11)
The Gemara in Megillah (16a) relates, that Haman told Mordechai to put on the royal clothes and then ride the horse of the king. Mordechai said, that he was unable to do so, until he had a haircut first, as it’s not respectful to wear the royal clothes without first having a haircut. Esther went around telling all the barbers to close, and Haman was left with no choice, but to perform the haircut himself.
The question is, the Mishnah in Avodah Zorah (27a) teaches, that it is forbidden to get a haircut from a non-Jew. R’ Meir forbids doing so in all places, whereas the Chachomim allow it in the reshus harabim [public domain], but not in private. If having a haircut from a non-Jew is forbidden, how was Mordechai allowed?
The Gevul Binyomin (Megillah 17a cited in Asifas Zekeinim) answers, that the Chachomim hold that it is allowed in a reshus harabim. When Haman gave Mordechai his haircut there were other people present, it was therefore considered like a reshus harabim and allowed.
The Gevul Binyomin (Megillah 17a cited in Asifas Zekeinim) offers a second answer. Tosfos in Avodah Zorah (29a) learns that the issur is when the barber is using a razor, and it is very easy to cause damage. If, however, the barber uses scissors where damage is not as likely it is allowed. Haman used scissors when giving Mordechai a haircut (as is clear from the Gemara), therefore, there was no issur involved.
The Madanay Asher answers: It’s clear from the Rishonim that the reason for the issur is that we are scared that the non-Jew will try and kill the Jew. In our case this was not of concern, as Achashveirosh had commanded Haman to get Mordechai prepared, and he was scared to disobey the king. Since he was scared, there was no concern of the barber trying to kill the Jew, therefore, it was allowed.
A second answer the Madanay Asher suggests, is that it’s clear from the Shulchan Aruch (Yoreh Deah, 157) that for an adam choshuv, important person, it’s different. Mordechai was an adam choshuv, therefore, it was allowed.
