The eagle under the cliff is paired with Xue Rengui, the Tang general whose rise from nothing is a favorite of opera and storytelling. He enlisted three times and was kept in the kitchens as a cook, while another officer's son-in-law claimed the credit for his feats in battle. His break came during the campaign against Goguryeo, when Emperor Taizong was cornered by the enemy commander and Xue rode in to save him. Recognized at last, he became the great general of the eastern campaign. Living low while keeping his bearing is exactly what the poem asks, and the hidden reward suits a middle stick: a hard, unseen stretch first, the summons later.