The rest of the Mao Quotation: "The ancient Chinese writer Sima Qian said, 'Though death befalls all men alike, it may be weightier than Mount Tai or lighter than a feather.' To die for the people is weightier than Mount Tai, but to work for the fascists and die for the exploiters and oppressors is lighter than a feather."

The quote is from one of the "Three Constantly Read Articles", i.e., Serve the People, written in memory of Zhang Side.