Brash had come at the invitation of Reuben Taipari of Ngapuhi, who said he wanted to hear the former politician's views.
Brash has said he would give a speech on the economy but would give no hint of its content before taking part in the pōwhiri.
He was unsure what reaction his speech would elicit but "we'll find out in due course".
Brash would not reveal the theme of his speech ahead of delivering it but said he had received a "very gracious" invitation to speak, and he accepted most invitations.
"This one was particularly significant, I thought, a chance to come back to Waitangi. As is well-known, I had a somewhat robust treatment last time.
"I respect the fact they're willing to listen to a view that may differ from theirs, that's fantastic," he told reporters.
Brash said it was "bizarre" that people thought he held racist views.
"What I believe, very strongly, is that all New Zealanders, irrespective of their ethnicity, irrespective of when they came, or when their ancestors came, to New Zealand, should have the same political rights."
He said it had crossed his mind that he might again be targeted with a muddy attack.
"But I'd be less inclined to walk away like I did last time."
The issue last time was around whether non-Māori media were allowed on to the marae.
However, the mud-slinging incident came a few days after Brash's Orewa speech.
Brash said the Treaty was being interpreted incorrectly. For example, there was no reference to partnerships in the document. All New Zealanders should be treated equally, he said.
"If Māori New Zealanders are disproportionately in prison, we should deal with the causes of imprisonment."
Brash said he was at Te Tii Marae to hear other views.
"Will they change my views? Let's see what they say."
