Much of "The Selected Work of Mao Zedong" is freely available online at [1]. Looking through the speeches readily available, I can't find any 1957 speech containing the content quoted above.

It looks the the only English language reference to the texted quoted above originates from a single Wikipedia edit from 2007 [2]. Neither the articles on "Re-education through labor" nor "Laogai" reference this quote.

It is my belief that this is likely a specious quotation. Mao likely did not say the text quoted.

[1] https://www.marxists.org/reference/archive/mao/selected-work... [2] https://en.wikipedia.org/w/index.php?title=Qincheng_Prison&o...