From Mao Zedong's 1935 ci-poem 《
忆秦娥·
娄山关》, written after the Red Army's victory at Loushan Pass during the Long March:
雄关漫道真如铁,
而今迈步从头越 — 'Say not the grand pass is truly like iron; today we stride over it and start anew.'
漫道 here is classical for
别说/
莫说 ('don't say'). A favorite in speeches on overcoming difficulty.