《资治通鉴·后梁纪·后梁纪四》
周德威秘密派出使者到晋王那里告急，此时晋王刚和后梁军相持在河上，想分兵救援，又觉得兵力太少，打算不去救援，又怕失去幽州。于是和诸将商量，只有李嗣源、李存审、阎宝劝晋王去解救幽州。
周德威遣间使诣晋王告急，王方与梁相持河上，欲分兵则兵少，欲勿救恐失之，忧形于色，谋于诸将，独李嗣源、李存审、阎宝劝王救之。
Zhou Dewang secretly dispatched messengers to inform the Prince of Jin about the urgent situation. At that moment, the Prince of Jin, who had met the Rebel Army in battle on the river, wanted to send troops for relief, yet his forces were too weak. He decided not to send any, but was worried he would lose Youzhou. He therefore consulted with several of his generals, and only Li Sixuan, Li Cunxu, and Yan Bao advised the Prince to go to Youzhou's aid.