If you your homework before dark, I will take you to the mall.  finish
had finished
will finish
finished

had finished this is your answer

had finished

Explanation:

hope it helps

1.the hosts on two opposing mountains stood,  

2.thick as the foliage of the waving wood;  

3.between them an extensive valley lay,  

4.o'er which the gleaming armour pour'd the day,  

5.when from the camp of the philistine foes,

6. dreadful to view, a mighty warrior rose; in the dire deeds of bleeding battle skill'd,