Ibn Majah

Hadith Commentary:
That is, their poisonous substance is so potent that if their sharp gaze collides with someone's eye, there is a fear of the loss of eyesight.
Similarly, for pregnant women, their sharp gaze is also dangerous for causing miscarriage.
Then, one cannot even estimate how deadly their poison itself would be.

(1) Lizards and other animals of this type are poisonous. If they fall into any food or drink, they make it poisonous to the extent that it can even cause death. Therefore, it is permissible to kill them. Although this narration does not explicitly mention a person in the state of ihram (muhrim), due to the reason of harm, he too can kill it.

(2) “In extinguishing the fire” — this is evidence that this animal (the lizard) is naturally harmful to humans; otherwise, how would it know whom the fire is going to burn? It should also be remembered that the permission to kill it is due to its natural harm, not because it assisted in the fire of Ibrahim alayhis salam, for that was the action of a specific lizard. The entire species cannot be punished for that, and for this, both prophet and disbeliever are equal. It will harm everyone.

(3) In the category of lizard are included other larger animals of the same type, such as the chalpasah, i.e., the karla, and other similar harmful animals.

(4) “Thin snakes that live in houses” — because they generally do not harm the inhabitants of the house. They do not even bite children. The command not to kill them is also based on the possibility that they may be a type of jinn, and it is not permissible to kill jinn. Furthermore, the reason for killing is harm; when they do not harm us, why should we harm them? Even the larger snakes that live in houses do not harm the inhabitants; rather, they become somewhat familiar with humans. However, snakes that live outside populated areas are harmful, so they should be killed immediately.

(5) “The two-striped (snake)” — this is very poisonous. The two stripes on its back are also due to its venom. Some scholars have said that it has two black marks on its forehead, etc.

(6) “Small snake” — small in body but extremely poisonous. It attacks suddenly and kills. Some have interpreted this as a snake with a short tail, but a snake does not have a separate tail. However, if the last part is called the tail, that is another matter.

(7) “They take away sight… etc.” — that is, if they bite or if one’s eyes meet theirs, sight is lost and a woman’s pregnancy is miscarried. And Allah knows best.