Jesus had appealed to the law's rule of two witnesses and named His Father as the second (John 8:17-18). The Pharisees asked where this witness was. Barnes says the question "was asked, doubtless, in derision," since "Jesus had often given them to understand that by his Father he meant God." Gill hears them scoffing, as if to say, "produce this witness boasted of, let us see him," or even, "it is Joseph the carpenter you mean." Matthew Henry says they could easily have understood "that when he spoke of his Father he meant no other than God himself." Their question treated a claim about God as a claim about an absent man.

Jesus did not point to a place. He answered, "Ye neither know me, nor my Father: if ye had known me, ye should have known my Father also" (John 8:19). Their question was "where," but His answer was about knowing. Barnes explains: if they had listened to His teaching and received Him as the Messiah, they "would also, at the same time, have been acquainted with God." John adds that Jesus spoke these words in the treasury, "and no man laid hands on him; for his hour was not yet come" (John 8:20).

The law required more than one witness to establish a matter (Deuteronomy 17:6; Deuteronomy 19:15), the passages Barnes connects to Jesus' words, "the testimony of two men is true" (John 8:17). The Pharisees had objected that Jesus was testifying about Himself (John 8:13). Jesus answered that He was not alone: He and the Father who sent Him both bore witness (John 8:16-18).

The "treasury" was in the temple, where Jesus was teaching (John 8:20). So this exchange happened in public, at the center of Israel's worship, among people who believed they knew God well.

This question shows how God makes Himself known. The Pharisees wanted the Father produced and pointed out, but Jesus said the Father is known through Him. Later Jesus would say almost the same words to His own disciples: "If ye had known me, ye should have known my Father also," and "he that hath seen me hath seen the Father" (John 14:7, 9).

The Pharisees thought they knew God and doubted Jesus. Jesus told them the opposite was true: missing Him meant missing the Father. God is not found by asking where He is hiding but by looking at the Son He sent.