Queen Kayla and Library of Leng

[The Desacrator]

Library of Leng
Queen Kayla bin-Kroog

Can I put the cards I discarded with her ability back on top of my deck to draw them again withe the same ability?

[WizardMN]

Yes, you can do that. Specifically, you can do that because discarding your hand is not part of the cost of the ability; it is part of its effect so Library can affect it. If you have 5 cards in hand (for example), you are free to use Library on 2 of them to put them on top and put the other 3 in your yard (or wherever else they might go) and then finish Kayla's ability putting any, or all, of those 3 onto the field.

Just note that whatever you discard to the top of your library cannot be put onto the field using Kayla.

[The Desacrator]

Thanks. One more question. If ibditch my whole hand can I put all back on top?

[WizardMN]

Sure. Though, if you put it all back on top, you will just draw all those same cards again. And you put nothing on the battlefield. So, unless you have something that cares about cards drawn or modifies the draws or something, you aren't really changing much beyond spending 4 mana and tapping Kayla.

[The Desacrator]

Just wanted to see if it could be done. Thanks a bunch