We know that God hath spoken unto Moses (ημεις οιδαμεν οτ Μωυσε λελαληκεν ο θεος). Perfect active indicative of λαλεω, so still on record. See Exodus 33:11. For λαλεω used of God speaking see Hebrews 1:1. They are proud to be disciples of Moses.

But as for this man, we do not know whence he is (τουτον δε ουκ οιδαμεν ποθεν εστιν). "This fellow" they mean by "τουτον" in emphatic position, we do not even know whence he is. Some of the people did (John 7:27), but in the higher sense none of the Jews knew (John 8:14). These Pharisees neither knew nor cared.