Chapter 12, Verses 5, 6, 7, 8, 9 and 10 - Sun Tzu

In attacking with fire, one should be prepared to meet five possible developments: (1) When fire breaks out inside to enemy's camp, respond at once with an attack from without. (2) If there is an outbreak of fire, but the enemy's soldiers remain quiet, bide your time and do not attack. (3) When the force of the flames has reached its height, follow it up with an attack, if that is practicable; if not, stay where you are. (4) If it is possible to make an assault with fire from without, do not wait for it to break out within, but deliver your attack at a favorable moment. (5) When you start a fire, be to windward of it. Do not attack from the leeward.
~ from The Art of War, Giles translation ~

Go here to read the introductory post to the verses of The Art of War.