The full quote reads "The world is yours, as well as ours, but in the last analysis, it is yours. You young people, full of vigor and vitality, are in the bloom of life, like the sun at eight or nine in the morning. Our hope is placed on you" (Shijie shi nimende, ye shi womende, danshi guigen jiedi shi nimende. Nimen qingnianren zhaoqi pengbo, zheng zai xingwang shiqi, haoxiang zaochen ba, jiudian zhongde taiyang. Xiwang jitou zai nimen shenshang - 世界是你们的，也是我们的，但是归根结底是你们的。你们青年人朝气蓬勃，正在兴旺时期，好象早晨八、九点钟的太阳。希望寄托在你们身上。)

Mao made this remark during a talk with Chinese exchange students and researchers in Moscow, 17 November 1957. It was included in the Little Red Book, at the start of chapter 30 "Youth".