Ibn Majah

Hadith Commentary:
First, the Lady of Paradise will lay claim to the blood of her two sons, Hasan and Husayn (radi Allahu anhuma), as is mentioned in another narration.
This does not contradict the fact that the first thing to be questioned about will be prayer (salah), because prayer is among the rights of Allah (huquq Allah), while bloodshed is among the rights of the servants (huquq al-‘ibad).
The meaning is that, among the rights of Allah, the first thing to be questioned about will be prayer, and among the rights of the servants, the first thing to be questioned about is unlawful bloodshed.
Whether the unlawfully shed blood belongs to a Muslim or a non-Muslim, the ruling is the same for both.
The light that is shed upon Islam’s concern for humanity through this is clearly evident and very manifest.

Hadith Commentary:
In the narration from Abu Hurairah radi Allahu anhu, it is reported that on the Day of Resurrection, the very first matter to be decided among the people will be concerning prayer (salah).
(Sunan an-Nasa’i, Kitab as-Salat, Hadith: 468)
The reconciliation between these two hadiths is as follows: among acts of worship, the first matter to be decided among the people will be concerning prayer (salah), and among matters of mutual dealings, the first cases to be settled will be those of murder.
In other words, it can also be said that among the rights of Allah (huquq Allah), the first thing to be questioned about will be prayer (salah), and among the rights of the servants (huquq al-‘ibad), the first thing to be questioned about will be murder.
In summary, the shedding of innocent blood—whether it be of a Muslim or a non-Muslim—is an extremely grave matter.
(Fath al-Bari: 12/234)

Hadith Commentary:
(1)
In matters of the rights of people (huquq al-‘ibad), the issue of taking a life is extremely grave; therefore, on the Day of Resurrection, these matters will be decided first. If, as a punishment for a crime, the Islamic government orders the execution of a criminal, this is not included among unlawful killings. Rather, for the executioner to carry out this duty due to the implementation of Islamic legal limits (hudud) is a source of reward.

(2)
In one hadith, it is stated that on the Day of Resurrection, the first thing for which a servant will be called to account is his prayer (salah).
(Musnad Ahmad: 103/4)
This hadith is not in contradiction to the aforementioned hadith, because in matters of worship, the first thing to be accounted for will be prayer, and in matters of the rights of people, the first thing to be settled will be the requital for unlawful bloodshed. Thus, in one narration, both have been mentioned together.
It is narrated from Abdullah ibn Mas‘ud radi Allahu anhu that the Messenger of Allah sallallahu alayhi wa sallam said:
“On the Day of Resurrection, the first thing for which a servant will be called to account is his prayer, and among the people, the first matter to be decided will be that of unlawful bloodshed.”
(Sunan al-Nasa’i, al-Muharaba, Hadith: 3996)

Explanation:
1:
This hadith (“The first thing for which a servant will be called to account is his prayer”) is not in contradiction,
because the judgment regarding blood relates to the mutual rights among people, whereas the hadith about prayer pertains to the rights of the Creator of the universe.
There is no doubt that among the rights of people, the greatest and most important matter about which one will be questioned is blood (i.e., matters of life and death),
and similarly, among the rights of Allah, the greatest matter about which one will be questioned first is the prayer (salah).

(1) Some have deduced from this hadith that on the Day of Resurrection, judgments will be made only among people, whereas the correct view is that first, judgments will be made among people, and then judgments will also be made among animals.

(2) This refers to the Day of Resurrection. Among the rights of Allah, the most important is the prayer (salah); therefore, its reckoning will be taken first. If one succeeds in this, then it is hoped that leniency will be shown in the rest of the rights of Allah as well. And if one fails in the prayer itself, then there will be no need to reckon the rest of the rights of Allah, or there will be no success in them. Among the rights of the servants (huquq al-‘ibad), the most important is the sanctity of life. If someone has violated this right, that is, has unjustly killed someone, then fulfilling the rest of the rights holds no meaning. And if a person is not caught in this right, then there is hope for salvation in the rest of the rights as well. It is thus understood that salvation depends on the judgment of these two matters, or the intent is to emphasize the importance of these two things: that among the rights of Allah, the reckoning of prayer will be first, and among the rights of the servants, the judgment regarding murder will be first. The rest of the reckoning and judgments will take place afterwards. However, the first meaning is more effective. And Allah knows best.

Benefits and Issues:
➊
Among the rights of the servants, the matter of taking a life is the most severe; therefore, on the Day of Resurrection, these matters will be decided first.

➋
Among acts of worship, the reckoning for prayer (salah) will be the first.

➌
Killing a criminal as a punishment under the order of an Islamic government is not included in unlawful killing; rather, for the executioner to carry out this duty due to the enforcement of Islamic legal limits (hudud) is a cause of reward.