《宋史·列传·卷一百二十三》
不久围困淮阳，贼兵坚守，攻城不下，贼兵预先与金人相约说 ：受围一天，则举烽火一只 ，到这时，六只烽火都举起来了，兀与刘猊都到达。
既而围淮阳，贼坚守不下，约曰： 受围一日，则举一烽。 至是，六烽具举，兀术与刘猊皆至。
Soon, he besieged Huaiyang, and the rebel army remained fiercely defensive, and the siege couldn’t be broken. The rebel army had previously made an agreement with the Jurchens that, if they were besieged for a day, a beacon fire would be lit. At the time, six beacon fires had been lit, and Wudi and Liu Ni both arrived.