Responsa do Izajasza 21:14

They responded: "For the thirsty, pour water!" (Isaiah 21:14) For those thirsty and desirous for words of Torah, pour some water. They further responded: the Torah only forbade the shaving of the head in order not to appear as idolaters, and anyone who is lenient in matters concerning idolatry, Heaven is lenient with his lifespan. Likewise, all who are strict with this, his days and years will be numerous.^*The reason for this commandment as idolatry is brought by Maimonides in Mishneh Torah, Foreign Worship and Customs of the Nations 12:1, and rejected by the Tur Yoreh Deah 181. Maimonides also allows the cutting of the sidelocks with scissors (ibid., 6).