The prophesies of Isaiah and their fulfilment in Matthew/Luke represents a gap of about 600 years. In actual fact the oldest prophecy in the Bible refers to the virgin birth – it is impossible to go back further in time, before humans were created! (We may be talking about 4,000 years between the time when the LORD spoke His word to Eve concerning her SEED and to the time of its fulfilment) and it is over 2,000 years since the birth of Jesus.