the 'Immediacy', is a name for that concentration of mind which is associated with such insight (vipassanā) as is present in any one of the 4 kinds of supermundane path consciousness (s. ariya-puggala), and which therefore is the cause of the immediately following consciousness as its result or 'fruition' (phala).
According to the Abhidhamma, the path (of the Sotāpanna, etc.) is generated by the insight into the impermanence, misery and impersonality of existence, flashing up at that very moment and transforming and ennobling one's nature forever.
It is mentioned under the name of ānantarika-samādhi in the Ratana Sutta (Sn.v.22) and in Pts.M.1, Ñānakathā.