rationalskepticism.org

If someone claims that whatever God does, or commands, is moral & good, then baby-killing is moral & good where God does it or commands it. It would therefore be immoral to oppose someone acting at God's command to kill babies. God clearly wouldn't allow anyone to act under the impression that they were commanded from God, unless they were in fact doing so. We must therefore conclude, that any person claiming to be acting in accord with God's will or command, even where they are intending to kill babies, is behaving in a moral & good way.

The alternative to this, is to say that killing babies is simply wrong & wholly immoral. Therefore God was wrong & acted immorally in his commands to Moses, and in his direct actions when he personally brought about the violent ends of children & babies.