The whole song is a play on German wedding vows.
The refrain ("Willst du, bis der Tod euch scheidet, treu ihr sein für alle Tage?") translates to "Do you want, until Death separates you all, to be faithful to her forever?" Instead of answering with "ja" ("yes"), the singer says "nein" ("no"), finally breaking his silence earlier in the song: "Du hast mich gefragt, und ich hab nichts gesagt", which translates to "You asked me, and I said nothing."
As stated earlier, the English version of Du Hast is not translated, but changed altogether ("Du hasst" (du haßt) means "you hate". The extra "s" differentiates it from the conjugated verb form of haben (to have).
Du: You
Du has(s)t: You have (hate)
Du has(s)t mich: You have (hate) me
Du hast mich gefragt: You have asked me
Du hast mich gefragt und ich habe nichts gesagt: You have asked me, and I have said nothing.
(wiki)
