Even till destruction sicken, answer me to what I ask you.
Speak. Demand. We'll answer.
Act 4 shows the apparitions telling Macbeth his fate and what to know.
Macbeth! Macbeth! Macbeth!... Beware Macduff!...none of woman born shall harm Macbeth...
... that bring you word Macduff is fled to England.
Fled to England?
The apparitions are telling Macbeth to beware of Macduff, that no woman born shall harm Macbeth, and that Macbeth can't be defeated unless Birnam Wood moves up to Dunsinane. He doesn't believe those are possible.
After finding out that Macduff fled to England, Macbeth out of free will decides to tell the murderers to murder Macduff's whole family. Macduff's family didn't have to do with anything but he made the choice to murder them.