The apparent meaning of the author’s words is that he is liable even if, at the time he unties the stopper, the contents are solid but are then melted by the sun; or if, at the time he unties the stopper, they are still, but the wind then causes them to spill. He is liable because he is an indirect cause.
His statement, “or a tether,” means that he finds, for example, an animal that is tied up, unties its tether, and it goes away; he is then liable for compensation.
His statement, “or a shackle, and what is in it goes away,” refers to a shackle placed on a restrained animal. The difference between a shackle and a tether is that the tether is fixed to the ground and the animal is tied to it, whereas a shackle is fastened to one or both legs, while the animal is still able to walk.
What the author—may Allah have mercy on him—has mentioned are examples and cases, not comprehensive rules. The rule, however, is that whoever destroys something is liable for compensation.
His statement, “or if he destroys something or the like, he is liable for it”: for example, suppose that the sheep for which he opened the door goes out and eats someone’s crops. The one who opened the door must compensate for the sheep and for the crops it destroyed. Likewise, if a bird collides with something and damages it, the one who opened its cage is liable for compensation. Similarly, if oil spills onto something and ruins it, he must compensate for the oil as well as for what it ruined. Thus, he is liable for the thing itself and for whatever results from it.
“If he ties an animal in a narrow road and a person trips over it, he is liable, just as with a vicious dog, in the case of someone who enters his house with his permission, or whom it bites outside his dwelling …”
His statement, “If he ties an animal in a narrow road and a person trips over it, he is liable”: the wording required by the context would have been, “and a person trips over it.”
In the author’s time there were no cars, while in our time there are no riding animals; yet one matter is compared to another. Thus, if he ties an animal in a narrow road and someone trips over it—