Let us see what Nathanael was doing before Philip meets him and calls him to go to encounter Jesus.
Among the Israelites there was a great desire and expectation for the Messianic age, the times of the Messiah, the famous millennium, which was an era of peace where people of all the world will be living in peace, there will be no more wars. This will be the millennial reign of the Messiah, when every Jew will be able to seat under the fig tree drinking the fruit of the vain. Micah 4:3-4
Well, what happen is, I imagine, that before Philip found Nethanael, he was going somewhere and was walking dreaming, thinking in the Messianic age and he imagined himself under the fig tree eating the produce of the vine in those beautiful times to come, when suddenly he met Philip who asked Nathanael to come with him because they have found the Messiah of whom Moses, the law and prophets spoke about. And Philip added, Jesus of Nazareth, the son of Joseph. So Nathanael doubted that anything good could come from Nazareth. It was a little town never mention in the Old Testament and also belonging to Galilee (of the gentiles). Which prophet could come from there? He was not at all impressed by what Philip said, so Philip had to push and say ‘come and see’.
On arriving Jesus told to the others gather there: here is an Israelite without fault, because he knew what he was thinking before Philip met him, and only a good Israelite will desire so much in his heart to have those days of peace to come.
We know that Philip was already with Jesus before he went to look for Nathanael, therefore Jesus was thinking in Nathanael and perceived that he was thinking in the Messianic age and saw what he was imagining.
We know that Jesus could read the thoughts of others (like when he went to the house of the Pharisee who wonder in his hart that if Jesus was a prophet he will know the type of woman who was cleaning his feet with her tears and drying them with her hair and Jesus gave an answer to his thoughts!!! Lk 39:40) also Jesus cured people at a distance, like the servant of the centurion Mt 8:8.
Now when Jesus spoke so well of Nathanael to the others, Nathanael asked Jesus, from where you know me, really as to speak like that of him.
And we know what Jesus answered him: “Before Philip called you, when you were under the fig tree, I saw you.”
YOU ARE THE SON OF GOD THE KING OF ISRAEL, Nathanael answered.
You can oppose my imaginations if you have a better one; I am note re-writing Scripture, just giving a new interpretation to a difficult passage.
In the love of Christ,