Nasai

Hadith Commentary:
Even from the perspective of human health, these animals are very harmful.
If each of these animals is considered in light of its harmful effects, then the statement of the Prophet (sallallahu alayhi wa sallam) becomes clearly understood.

Hadith Commentary:
These five animals, as much as they are harmful, it is evident that by commanding their killing, the Lawgiver (sallallahu alayhi wa sallam) has guided mankind towards solutions for many issues related to wealth, physical well-being, economy, and food. The crow and the kite are notorious for robbery, the scorpion for its stinging (injecting venom), the rat is harmful to human health and an enemy of food stores, and the biting dog is extremely dangerous to health.
This is the very reason why their killing has been permitted everywhere.

Hadith Commentary:
(1)
These five animals are extremely dangerous and harmful.
They have adopted a path distinct from other animals in causing harm and spreading corruption, which is why they have been called "fasiq" (transgressors).
The Messenger of Allah (sallallahu alayhi wa sallam), by commanding that they be killed both inside and outside the Haram, has drawn our attention to financial, physical, economic, and dietary issues.

(2)
The crow and the kite are notorious for robbery.
The crow pecks at the back of a camel.
If the camel is weak, it gouges out its eye.
In addition, it snatches people’s food.
Similarly, the kite also snatches meat.
The scorpion is notorious for stinging.
Its sting causes great pain.
The rat is harmful to human health, an enemy of food stores, and by pulling the wick from a lamp, it can burn down an entire house.
A rabid dog is also extremely dangerous to human health.
It injures people.
All the scholars agree that it is permissible to kill them while in the state of ihram, and they may also be killed within the Haram.

(3)
From this, it is also understood that if a criminal deserving of death takes refuge in the Haram, there is no harm in bringing him to justice.
(Fath al-Bari: 4/54)

Hadith Commentary:
Vocabulary of the Hadith:
(1)
AL-IQ‘Ā’:
There are two forms of iq‘ā’:
(1)
Placing one’s buttocks on the ground, raising the shins upright, and spreading the hands on the ground like a dog—
this, by consensus, is prohibited, and in another hadith, it has been forbidden.
(2)
Sitting between the two prostrations (sajdahs) by placing one’s buttocks on the feet (heels)—
Ibn Abbas radi Allahu anhu considers this a Sunnah,
and the Companions,
the hadith scholars, and Imam Shafi‘i rahimahullah deem it permissible.
(2)
JAFĀ’:
Heaviness and hardship,
ill-manners.
al-rijl:
If it is read as “rijl,” it means “foot,” and if read as “rajul,” it means “man”—that sitting in this manner is a cause of heaviness and hardship for a person.
Benefits and Issues:
There is no authentic hadith establishing any difference in posture or manner between the prayer of men and women, and the form of iq‘ā’ is for the person for whom sitting in this manner is convenient and easy.

1:
By "biting dog" is meant all those predatory animals that attack people and injure them, such as lions, leopards, wolves, etc.

These discussions have already passed previously. The difference is that there, the mention was of the muhrim (one in the state of ihram), and here, the mention is of the Haram (sanctuary). In other words, these animals may be killed by a muhrim, whether inside or outside the Haram. And in the Haram as well, they may be killed, whether the one killing is a muhrim or a person in a state of permissibility (halal). The reasons for their killing have already been explained previously. (For details, see Hadith: 2831 to 2838) The permissibility of killing them means that the killer will not have to give any recompense, expiation, or penalty.

The harmfulness of the snake is evident. In the above narration, instead of the snake, the scorpion is mentioned. Both are from among the creatures of the earth and are venomous; therefore, both can be counted as belonging to the same category. The mention of one suffices for the mention of the other. Other biting insects can also be included under this ruling.

Benefits and Issues:
A "fasiq" is a sinner.
It refers to an immoral and wicked person.
These animals are called "fasiq" because they cause great harm to humans.

601 Lexical Explanation:
«الدّوَابّ» "Ba" has a shaddah (emphasis) on it. This is the plural of «دابة». It refers to every animal that crawls on the earth, that is, walks, and then generally its usage became common for four-legged animals.

«فَوَاسِق» is the plural of «فاسقة», and their wickedness and evil is due to their filthiness, abundance of harm, and being injurious.

«الحِدَأة» is with a kasrah (i) on the "Ha". It is on the pattern of «عِنبَة». It is called a kite (cheel). It is such a filthy bird that it snatches meat from a human's hand and flies away.

«العَقْرَب» means scorpion. In its meaning, snake is included even more so.

«وَالْكَلْبُ الْعَقُور» «العقور» is with a fatha (a) on the "Ayn", and is derived from «عقر», which means to kill and to wound. By this is meant every beast that tears and rends, such as lion, leopard, panther, bear, and wolf, etc.