Based on Chapter 51, what is the significance of Arjuna's specific phrasing when he tells Krishna his delusion has vanished?

Chapter 51 provides a deep analysis of Arjuna's response to Krishna. The text highlights that after Krishna's discourse, Arjuna states, "My delusion has vanished to the ends of the earth." Crucially, he does not claim to have "'attained' knowledge." Chapter 51 explains the importance of this distinction, clarifying that the destruction of delusion is the key outcome. The chapter posits that "delusion (moha) is merely another name for ignorance," and the true essence of spiritual progress, as understood by those who know the Gita, is the removal of this ignorance rather than the acquisition of something new. This insight is a key point made within Chapter 51.