Kesha Dhatu - the Buddha's hair relics.
In the Anuradhapura Kingdom, which spanned from the 4th century BCE to the 11th century CE, there was a Pali Chronicle known as "Kesha Dhatu Vamsa" Which focused on The Buddha’s hair relics. Although it was a substantial book, it no longer exists, and we are unable to access it today.
There is a book called "The Chakesadhatuvamsa" or "Chronicle of the Six Hair Relics of the Buddha" that was written in Myanmar. The book is written in Pali Language, but an English translation is also available. According to the text, the Buddha gave six of his hairs to his disciples in Venuvana, Rajgir. These hairs were then distributed to six bordering countries that had never seen the Buddha. The book also mentions that during his sermons in Mon State, the Buddha gave six of his hairs to hermits, including a pair of Belu brothers named Tapassu and Ballika from Kyaikhtisaung. All of the hermits and Belus enshrined the hair in large stones.
As per the Pali commentary, the Buddha's hair possesses five distinctive traits. Firstly, it bristles, and secondly, it is black in color. Thirdly, it resembles the hue of collyrium. Fourthly, it curls, and fifthly, it twists towards the right.
The 80 minor characteristics of the Buddha are extensively featured in Pali literature's Apadāna, Milindapañha, and Buthsarana texts, making them highly significant in both the Mahāyāna and Theravāda traditions.
According to the Jataka Commentary, it was stated that the length of Buddha's hair was two inches.
According to the Theravada tradition, at the age of 29, Prince Siddhartha underwent the 'Great Renunciation' (Mahabhinishkramana) from his palace. He ordained himself as an ascetic on the banks of the Neranjana river. The prince cut his hair with a royal sword and threw it into the air. The King of the Gods, "Sakkha," received the hair with his own hands, as he knew that Prince Siddhartha would eventually become the Buddha. Sakkha deposited the sacred hair relics in a golden casket and went to his heavenly abode in "Thawthisa." There, he created a great stupa out of gemstones using his divine power, called Culamani cetiya or "Silumini Seya," and deposited the hair relics inside it. This stupa is said to exist even today and was the first stupa made by enshrining the Buddha's Hair Relics. The rest of the Buddha's hair remained two inches long and turned right until he passed away. He never trimmed or shaved it after his ordination. There are also hair relics after his enlightenment.
As you may be aware, Gautama Buddha spent seven weeks around the Bodhi tree. In the seventh week after his Enlightenment, he meditated under the 'Rajayathana' tree. On the fiftieth day, after fasting for seven weeks, two merchants named Tapassu and Bhallika from Ukkalapada, Utkal, or the modern state of Orissa in India, came to his presence while they were touring for trade. They offered the Buddha rice cakes and bees' honey to break his fast. This story is recorded in Anguttara Nikaya Commentary - Manorathapurani.
After listening to Buddha's teachings, these two merchants became the first lay followers of our Buddha and took refuge in Buddha and Dhamma.
The merchants requested something sacred to keep with them as a symbol of reverence, and Gautama Buddha responded by wiping his head with his right hand and giving them eight handfuls of his hair.
According to legend, while traveling, Thapassu and Bhalluka visited a city called Asitanjana in the Gandhara Kingdom (now part of Pakistan and Afghanistan) and constructed a Stupa there. The commentary mentions that the Stupa emitted a blue glow on every full moon night. In the 7th century, the renowned Chinese traveler, Huen Tsang, visited the Stupa and noted that there were two stupas built by Thapassu and Bhalluka in separate cities named Tirei and Poli. Both stupas were approximately 60 feet tall. As the region is now located in Pakistan and Afghanistan, the exact location of these stupas remains unknown.
Rajayatana trees (B. cochinchinensis) at the Mahabodhi Temple complex in Bodh Gaya, Bihar, India
Thapassu and Bhallika had a tradition of carrying sacred hair relics in a casket during their overseas trade voyages. On one such journey in the Eastern Province of Sri Lanka, they took a break at a secluded spot near a rocky hill. They placed the casket on top of the rock overnight and the next day, when they were ready to leave, they found that they couldn't move the casket from its spot. Understanding that it was a sacred location, they constructed a small stupa using the available stones to cover the casket and departed.