What are the allusions of Yang Liulang's victory over the enemy?

In the Song Dynasty, Yang Liulang was ordered to lead troops to Bazhou to resist the invading Liao soldiers.

It was late autumn and early winter, and it was freezing. As soon as he arrived in Bazhou, Yang Liulang ordered the soldiers to fortify the walls and prepare to meet them.

The scouts of Liao country noticed this situation and reported it to the commander in chief. After hearing this, the head coach decided to take advantage of Yang Liulang's unstable foothold to launch an attack. He aggressively sent emissaries to the Song military camp to spy on the military situation.

The messenger returned to the camp and reported to the Commander-in-Chief that the wall of Song Jun was less than ten feet high, and the soldiers in Song Jun were exhausted from building the city. The commander-in-chief of Liao army was even happier after hearing the news. He ordered his troops to have a good rest and save their strength, and defeated Song Jun in one fell swoop three days later.

Yang Liulang off the angel of the Liao army, immediately ordered the soldiers to stop fortification, enter an item in an account to sleep during the day, and draw water in shifts at night to water the city. For three days and nights.

On the day of the decisive battle, the Liao army beat drums and urged the horse to pounce on Bazhou City, thinking that it could jump over the low wall and capture Bazhou in one fell swoop. Who knows, when I came to the gate, I saw not the earth wall more than ten feet high, but the glittering ice wall more than ten feet high.

Commander-in-chief of Liao army knew something fishy about it, but he still ordered his men to forcibly attack the city because of his strength. But as soon as Liao soldiers approached the ice wall, they slipped and went belly-up. Song Jun entered the city earlier and earlier, and an arrow shot at Liao Army like a migratory locust. Song Jun, who was ambushing in the Woods on both sides, also took advantage of the situation to fight, and the Liao army was caught off guard and fled in all directions.

Natural conditions, such as weather, often have a great influence on the outcome of war. Yang Liulang can win more with less, because he can take advantage of the cold weather characteristics and natural conditions, wait for an opportunity to get out early and defeat the enemy.