John 7:1 RSV After this Jesus went about in Galilee; he would not go about in Judea, because the Jews sought to kill him. 2 Now the Jews’ feast of Tabernacles was at hand. 3 So his brothers said to him, “Leave here and go to Judea, that your disciples may see the works you are doing. 4 For no man works in secret if he seeks to be known openly. If you do these things, show yourself to the world.” 5 For even his brothers did not believe in him. 6 Jesus said to them, “My time has not yet come, but your time is always here. 7 The world cannot hate you, but it hates me because I testify of it that its works are evil. 8 Go to the feast yourselves; I am not going up to this feast, for my time has not yet fully come.” 9 So saying, he remained in Galilee.
John 7:10 But after his brothers had gone up to the feast, then he also went up, not publicly but in secret.
Jesus statement in verse eight “I am not going up to this feast ...” ἐγὼ οὐκ ἀναβαίνω εἰς τὴν ἑορτὴν ταύτην caused difficulties for at least one early scribe who replaced the negative particle οὐκ “I am not going up to this feast” with οὔπω “I am not yet going up to this feast.” The reading οὔπω is found in several early manuscripts (p66, p75, B). The theological motivation for this variant is fairly obvious, to remove the appearance that Jesus lied to his brothers.
On the other hand, a close reading of the pericope removes the difficulty. Jesus’ brothers were not just asking him to go up to the feast in Jerusalem. The main thrust of their request was that Jesus should go up publicly: “... show yourself to the world.” The scenario that Jesus’ brothers envision includes a demonstration of Jesus’ works before his disciples and the rest of world. Jesus rejects this entire scenario with a simple statement “I am not going up to this feast.” Going up to the feast secretly is not the scenario suggested by Jesus’ Brothers. 
 see Robert Horton Gundry, Commentary on the New Testament: Verse-by-Verse Explanations with a Literal Translation, p. 388.