I remember reading about one sutta "emptiness in small gap". Since consciousness (Vijñāna) raises and falls all the time, between each consciousness there is a very small and briefest gap where Vijñāna doesn't take place. If i remember correctly, Buddha might have said about this emptiness as FYI. Anyone could help me find sutta about "emptiness in small gap" or "emptiness in small space", or "void in tight space". i want to study this sutta again to see if buddha ralated this emptiness to vimutti or maha-sunyata. thanks
I have never read a Sutta talking about emptiness in terms of a gap or a small space, and to my knowledge the Suttas don't explicitly talk about what happens between individual consciousnesses (although the commentaries on the Suttas do interpret certain passages as referring to it).
Within the Theravada Abhidhamma, this issue is taken up more explicitly. According to the Abhidhamma, between individual consciousnesses there is another type of mind-state called the Bhavanga-citta. The Ven. Bhikkhu Bodhi in his book A Comprehensive Manual of Abhidhamma explains the Bhavanga quite succinctly as follows on page 106:
(2) Life-continuum (bhavanga): The word bhavanga means “factor (anga) of existence (bhava),” that is, “the indispensable condition of existence.” Bhavanga is the function of consciousness by which the continuity of the individual is preserved through the duration of any single existence, from conception to death. After the paṭisandhicitta has arisen and fallen away, it is then followed by the bhavangacitta, which is a resultant consciousness of the same type as the paṭisandhicitta but which performs a different function, namely, the function of preserving the continuity of individual existence.
Bhavangacittas arise and pass away every moment during life whenever there is no active cognitive process taking place. This type of consciousness is most evident during deep dreamless sleep, but it also occurs momentarily during waking life countless times between occasions of active cognition. When an object impinges on a sense door, the bhavanga is arrested, and an active cognitive process ensues for the purpose of cognizing the object. Immediately after the cognitive process is completed, again the bhavanga supervenes and continues until the next cognitive process arises. Arising and perishing at every moment during this passive phase of consciousness, the bhavanga flows on like a stream (sota), without remaining static for two consecutive moments.