Shvetaketu's Teaching
A father teaches his son the ultimate truth.
Uddalaka teaches his son Shvetaketu that Brahman is the subtle essence of all, repeated with the refrain 'Tat tvam asi' - 'That thou art.'
This subtle essence - that is the Self of all. That is Reality. That is the Self. That thou art, Shvetaketu.
This dialogue beautifully illustrates parental spiritual transmission.
Chandogya Upanishad