And never is it for a believer to kill a believer except (4:92)

Almuntakhab Fi Tafsir Alquran Alkarim

Observe particularly: It is not right for a believer who has conformed to Islam to kill another believer of the same law unless it be by mistake. And he who kills a Muslim by chance and guilt does not reside in the intention shall run into some consequences in expiation of his wrong, thus

Tafseer Tafheem-ul-Quran by Syed Abu-al-A'la Maududi

(4:92) It is not for a believer to slay another believer unless by mistake. *120 And he who has slain a believer by mistake, his atonement is to set free from bondage a believing person *121 and to pay blood-money to his heirs, *122 unless they forgo it by way of charity. And if the slain belonged to a hostile people, but was a believer, then the atonement is to set free from bondage a believing person.

And if the slain belonged to a (non-Muslim) people with whom you have a covenant, then the atonement is to pay the blood-money to his heirs, and to set free from bondage a believing person. *123 But he who cannot (free a slave) should fast for two consecutive months. *124 This is the penance ordained by Allah. *125 Allah is All-Knowing, All-Wise.

And never is it for a believer to kill a believer except meaning

*120). The hypocritical confessors of Islam mentioned here are distinct from those whom the Muslims may kill. The reference here is to Muslims who are either residents of the Domain of Islam (Dar al-Islam) or to those who live in the Domain of War or of Unbelief (Dar al-Harb or Dar al-Kufr) but against whom there is no proof of actual participation in the hostile activities with the enemies of Islam. In the time of the Prophet (peace be on him) there were many people who had embraced Islam and yet, because of genuine difficulties, were living among tribes hostile to Islam. It occasionally happened that, in attacking a hostile tribe, the Muslims inadvertently killed fellow Muslims living in its midst.
*121). Since the person killed was a believer, expiation of the sin required the emancipation of a Muslim slave.
*122). The Prophet (peace be on him) had fixed the blood-money at either 100 camels, 200 oxen or 2,000 head of cattle. If someone wished to pay this in another form the amount would be determined with reference to the market value of the articles mentioned above. For instance, for those who wished to pay blood-money in cash, the fixed amount in the time of the Prophet (peace be on him) was 800 dinars (8000 dirhams). In the time of Caliph 'Umar the amount of blood-money was fixed at 1000 golden dinars (12000 silver dirhams). It should be noted, however, that this amount relates to an unintentional rather than a deliberate homicide. (Regarding blood-money for unintentional homicide and injury see Abu Da'ud, 'Diyat', 14-17; Tirmidhi, 'Diyat', 1; Nasa'i, 'Qasamah', 34; Ibn Majah, 'Diyat', 6; Malik b. Anas, Muwatta', "Uqul', 4; Ahmad b. Hanbal, Musnad, vol. 1, pp. 384 and 450; vol. 2, pp. 178, 183, 186, 217, 224; vol. 4, p. 275. See also Ibn Rushd, Bidayat al-Mujtahid, vol. 2, pp. 401 ff. - Ed.)
*123). The legal injunctions embodied in this verse are as follows:
(1) If the victim was a resident of the Domain of Islam (Dar al-Islam) the killer is not only required to pay blood-money but also to emancipate a slave by way of expiation.
(2) If the victim was a resident of the Domain of War (Dar al-Harb) the killer is only required to emancipate a slave.
(3) If the victim was a resident of a non-Muslim country which had treaty relations with an Islamic state the killer is required to emancipate a slave and also to pay blood-money. The amount of the blood-money, however, depends on the terms stipulated in the treaty between the Muslims and the territory of the victim. (See Jassas, vol. 2, pp. 238 f f. and 240 ff. - Ed.)
*124). This means that he should observe fasting uninterrupted for the entire period. If a man breaks his fast for just one day without a legally valid reason he will be required to resume fasting anew.
*125). This shows that what has been prescribed is an act of repentance and expiation rather than a penalty inflicted on a criminal. Penalization is essentially devoid of the spirit of repentance and of the urge to self-reform. A penalty is suffered under duress, usually with resentment, and leaves behind repugnance and bitterness. On the contrary, what God wants is that the believer who has committed a sin should wash the stain of it from his soul by supererogatory worship, by acts of charity, and by a meticulous fulfilment of all the duties incumbent upon him. Such a person is required to turn to God in remorse and repentance so that his sin may be pardoned and his soul secured against the recurrence of similar errors.
The word kaffarah signifies that which either covers or hides something. To declare that certain acts of charity constitute kaffarah means that those acts overlay the sin and cover it up, just as stains on a wall are covered up when it is painted.
 

And never is it for a believer to kill a believer except meaning in Urdu

کسی مومن کا یہ کام نہیں ہے کہ دوسرے مومن کو قتل کرے، الا یہ کہ اُس سے چوک ہو جائے، اور جو شخص کسی مومن کو غلطی سے قتل کر دے تو اس کا کفارہ یہ ہے کہ ایک مومن کو غلامی سے آزاد کرے اور مقتول کے وارثوں کو خونبہا دے، الا یہ کہ وہ خونبہا معاف کر دیں لیکن اگر وہ مسلمان مقتول کسی ایسی قوم سے تھا جس سے تمہاری دشمنی ہو تو اس کا کفارہ ایک مومن غلام آزاد کرنا ہے اور اگر وہ کسی ایسی غیرمسلم قوم کا فرد تھا جس سے تمہارا معاہدہ ہو تو اس کے وارثوں کو خون بہا دیا جائے گا اور ایک مومن غلام کو آزاد کرنا ہوگا پھر جو غلام نہ پائے وہ پے در پے دو مہینے کے روزے رکھے یہ اِس گناہ پر اللہ سے توبہ کرنے کا طریقہ ہے اور اللہ علیم و دانا ہے