About the poem (from Wikipedia):
Samson Agonistes is a tragic closet drama by John Milton. It draws on the story of Samson from the Old Testament, Judges 13–16; in fact it is a dramatisation of the story starting at Judges 16:23. The drama starts when Samson has been captured by the Philistines, has his hair, the container of his strength, cut off and his eyes cut out. Samson is “Blind among enemies, O worse than chains” (line 66).
Samson Agonistes combines Greek tragedy with Hebrew Scripture, which alters both forms. Milton believed that the Bible was better in its classical forms than those written by the Greeks and Romans. In his introduction, Milton discusses Aristotle’s definition of tragedy and sets out his own paraphrase of it to connect it to Samson Agonistes.
Acts of violence are an important theme within Samson Agonistes as the play attempts to deal with revenge and the destruction of God’s enemies. The play itself suggests the horror within the actions through descriptive phrases, including “evil news” (line 538), “this so horrid spectacle” (line 1542), “the place of horror” (line 1550) and “the sad event” (line 1551).
The play, focusing around the betrayal of Samson at the hands of Dalila, his wife, produces a negative portrayal of love and love’s effects. Women, and men’s desire for women, are connected to idolatry against God and the idea that there is no possibility for the sacred within the bonds of marital love. Samson, who is both holy and desirous of Dalila, is seduced into betraying the source of his strength, and thus betrays God. He is emasculated, through blindness, because of his sexual desires.