User blog comment:Miskos3/Fairy Tail Chapter 367: Jellal vs. Oracion Seis, Review/@comment-24257713-20140117114753/@comment-24257713-20140117132031

The reason why Jellal said that is two things:

One, they're still bound to Brain/Zero. I don't know how. I don't know why. But they're still bound to him in some way.

Two, he wanted to give them a second chance other than his imposed slavery at the Tower of Heaven.