Obama Almost Quotes Rev. Wright When He Says, "These guys love to
throw a rock and hide their hand."

On ABC's "This Week" with George Stephanopoulos, on September 7,
2008, in talking about rumors relating to Obama's being a Muslim,
Obama said, "These guys love to throw a rock and hide their
hand."

I did an Internet search on a search engine for the following
search statement:  "hide their hand" Wright.  

Here is part of what I found.  

Trinity Church of Christ, Chicago, Il
Sermon: Watch Out For People Who Would Throw A Brick and Then
Hide Their Hand Rev. Dr. Jeremiah A. Wright

The sermon is on YouTube.com.  

Is it not obvious that Obama was simply paraphrasing Rev. Wright
by substituting the word "rock" for "brick"?  

Also, why doesn't Obama give credit to Rev. Wright for his words?
Is this another case of plagiarism?