I don't understand how I should understand this sentence word by word: 农夫过去一看. Without "guo4" everything is clear for me, since "qu4 yi2 kan4" means "to take a look".
But with "guo4" I don't know if it's "Nong2fu1 guo4qu4 yi2kan4" - in this case I don't understand what "yi2" is doing here - or "Nong2fu1 guo4 qu4yi2kan4" - then I don't understand the role and meaning of "guo4". The whole sentence must mean "The farmer came to take a look"... The whole context:
老虎倒在了芦苇丛里。农夫过去一看,老虎前胸插着箭。