Up means close and nayan means to take away. To be taken close to the Guru (teacher) means the Upanayan sanskar (Yagyopavit Sanskar). Even today this tradition is practiced. Janaeu means Yagyopavit has three main sources and these three gods- trinities- Brahma, Vishnu, are the symbols. The child receives strength, energy and strength from this sacrament.
Significance of Yagyopavit Sanskar:
The Rig Veda showcases that some of the characteristics of Upanayan Sanskaras described in the Grihayasutras were also known at that time. There is a praise of Yup (sacristy) like a young man "Here the young man is coming, he is well-equipped When he is born, he receives the importance; Hey Clever sages, you have reverence for God in your heart and are healthy thoughts, raise it up!
"There is the
same word present in" Unnayati "here, which is in the Upanayan. Many
legends have cited this mantra, such as Ashvalayan, Paraskar. There is a
mention of the words- 'Brahmachari' and 'Brahmacharya' in the description in
the Taitriya Samhita. When Brahmin is born, he is indebted of the three
classes’ people; one is during Brahmacharya towards the sages (indebted), in
the Yajna towards gods and in the saints towards ancestors; who so ever
conducts Yajna, who has son and the person who stays along with his teacher,
hence these get free from all the debts. Description of Upaniyan and
Brahmacharya texts are available in Vedas and Brahmin literature.