The Records of the Three Kingdoms is a Chinese historical text which covers the history of the late Eastern Han dynasty (c. 184–220 CE) and the Three Kingdoms period (220–280 CE). – Wikipedia
According to most scholars, this is the oldest historical record that speaks of Jeju. There is some dispute over whether Juho refers to Jeju or another island.
The original Chinese is taken from the website of 한국사데이터베이스 – 국사편찬위원회 and my translation relied on the translations into Korean by 장창은 and 고창석.
其北方近郡諸國差曉禮俗, 其遠處直如囚徒奴婢相聚. 無他珍寶. 禽獸草木略與中國同. 出大栗, 大如梨. 又出細尾雞, 范書, 作長尾鷄. 其尾皆長五尺餘. 其男子時時有文身. 又有州胡 在馬韓之西海中大島上, 其人差短小, 言語不與韓同, 皆髡頭如鮮卑, 但衣韋136, 好養牛及豬. 其衣有上無下, 略如裸勢. 乘船往來, 市買韓中.
Juho is on a large island in the middle of the ocean to the west of Mahan. Most of the people there are short and their language is unlike that of the Han. They all shave their heads like the Xiānbēi and only wear leather clothing. They are fond of raising cows and pigs. They go about semi-nude, only wearing clothing on the upper halves of their body. They go back and forth to the central Han region on boats to buy and sell goods.