Bava Kamma 6A

לאתויי ליחכה נירו וסכסכה אבניו.

The Talmud answers: It serves to add cases where the fire scorched another’s plowed field and cases in which it singed his stones. Even though the damaged object remains intact and is not consumed by the fire, one is still liable to pay for the damage caused.

הצד השוה שבהן. לאתויי מאי? אמר אביי: לאתויי אבנו סכינו ומשאו שהניחן בראש גגו, ונפלו ברוח מצויה והזיקו.

§ The Mishnah teaches: The common denominator of the components in all these categories is that it is their typical manner to cause damage. The Talmud asks: In order to add what halakha is this statement cited in the Mishnah? Abaye said: The stating of the common denominator in the Mishnah serves to add that one is liable in a case of his stone, his knife, or his load, where he placed them on top of his roof, and they fell off the roof by means of a common wind and caused damage.

היכי דמי? אי בהדי דקא אזלי קא מזקי ⁠– היינו אש!

The Talmud asks: What are the circumstances in which one would be liable for the damage that was caused? If it is a case where those items cause damage as they are moving through the air propelled by the wind, that is a subcategory of Fire.

מאי שנא אש ⁠– דכח אחר מעורב בו, וממונך ושמירתו עליך; הני נמי, כח אחר מעורב בהן, וממונך ושמירתו עליך!

Therefore, one could claim: If so, what is different about Fire that defines it as a unique category? It is that another force is involved with it in causing damage, as it is the wind that causes the fire to spread and cause damage; and the entity propelled by the wind is your property, and responsibility for its safeguarding, to prevent it from causing damage, is incumbent upon you. In these cases, too, another force is involved with them in causing damage; and the objects are your property, and responsibility for their safeguarding, to prevent them from causing damage, is incumbent upon you. Perforce, there is no need for the common denominator in the Mishnah to teach the case of an object that causes damage when propelled off a roof by the wind. That case is included in the primary category of Fire that is explicitly mentioned in the Mishnah.