This excerpt is taken from Sheikh Farooq Rafi Sahib's book Qurbani, Aqiqah, and Ashra Zil-Hijjah.
While slaughtering the sacrificial animal, it is permissible and recommended to say only Bismillah, and at the very least, saying Bismillah is obligatory when slaughtering the animal.
❀ Sayyiduna Jundub bin Sufyan (may Allah be pleased with him) narrates that the Messenger of Allah (peace be upon him) said:
من ذبح قبل الصلاة فليذبح شاة مكانها ومن لم يكن ذبح فليذبح على اسم الله
"Whoever slaughtered before the Eid prayer should slaughter a replacement goat or sheep, and whoever did not slaughter until the Eid prayer should slaughter the animal saying Bismillah."
Reference: Sahih Bukhari, Book of Slaughtering and Hunting, Chapter: The Prophet (peace be upon him) said: Slaughter in the name of Allah: 5500, Sahih Muslim, Book of Sacrifices, Chapter: Its Time: 1960, Sunan an-Nasa'i: 4403, Sunan Ibn Majah: 3152
Benefits:
فليذبح على اسم الله means to slaughter by saying Allah, and this is the commonly accepted meaning.
Reference: Sharh An-Nawawi: 111/13.
It is for the command of obligation, therefore it is obligatory to say Bismillah while slaughtering an animal. Also, saying Bismillah at the time of slaughtering is the personal practice of the Prophet ﷺ. Sayyida Aisha رضي الله عنها narrates that when the Messenger of Allah ﷺ began to slaughter the sacrificial sheep, he said:
بسم الله، اللهم تقبل من محمد و آل محمد، و من أمة محمد، ثم ضحى
Bismillah (In the name of Allah), O Allah! Accept it on behalf of Muhammad, the family of Muhammad, and the nation of Muhammad ﷺ! Then he ﷺ slaughtered the animal.
Reference: Sahih Muslim: 1967. Sunan Abi Dawood, 2792. Musnad Ahmad: 78/6. Sunan Bayhaqi: 267/9.
It is a recommended act to say Bismillah and Allahu Akbar while slaughtering an animal because it is also proven from the Messenger of Allah ﷺ that he used to say these words while slaughtering an animal. ❀ Sayyiduna Anas bin Malik رضي الله عنه narrates:
ضحى النبى صلى الله عليه وسلم بكبشين يسمي ويكبر
"The Prophet ﷺ slaughtered two rams (and while slaughtering them) he said Bismillah and Allahu Akbar."
Reference: Sahih Bukhari, Book of Tawheed, Chapter on Asking the Names of Allah: 7399. Sahih Muslim, Book of Sacrifices, Chapter on the Recommendation of Appreciating the Sacrifice: 1966.
Imam Nawawi رحمه الله states that this hadith is evidence that saying Bismillah while sacrificing and slaughtering other animals is established and it is a matter of consensus.
Also, saying Bismillah and Allahu Akbar while slaughtering an animal is a recommended act.
Reference: Sharh Nawawi: 121/13. Nayl al-Awtar, 129/5.
It is a matter of difference of opinion among scholars whether it is recommended or disliked for the person offering the sacrifice to mention their name and say the specified words while slaughtering the sacrificial animal.
The majority of scholars consider it a recommended act to say اللهم تقبل مني (O Allah! Accept this sacrifice from me) and اللهم منك و لك عن فلان (This sacrifice is from so-and-so, for You and to You) along with "Bismillah wa Allahu Akbar" when slaughtering the sacrificial animal. Allah Almighty says:
﴿وَمَا أُهِلَّ بِهِ لِغَيْرِ اللَّهِ﴾
The animal on which the name other than Allah is invoked is unlawful.
Reference: Al-Baqarah:173
Imam Malik states that saying اللهم منك ولك at the time of sacrifice is a disliked act and an innovation.
Reference: Sharh al-Nawawi: 122/13. Al-Mughni with Al-Sharh al-Kabir: 118/11.
Prevailing School of Thought:
The prevailing opinion among the majority of scholars in this matter is as follows, and the evidence for it being closer to the truth is as follows:
① Sayyida Aisha (may Allah be pleased with her) narrates that the Messenger of Allah (peace be upon him) said these words when slaughtering a ram:
اللهم تقبل من محمد و آل محمد و من أمة محمد
O Allah! Accept it on behalf of Muhammad, the family of Muhammad, and the nation of Muhammad (peace be upon him)!
Reference: Sahih Muslim: 1967. Sunan Abi Dawood, 2792, Musnad Ahmad, 78/6 - Sunan Bayhaqi: 267/9.
Benefits:
① Imam Nawawi, may Allah have mercy on him, states:
فيه دليل لاستحباب قول المضحى حال الذبح مع التسمية والتكبير اللهم تقبل مني، قال أصحابنا : ويستحب معه اللهم منك وإليك تقبل مني
This hadith is evidence that it is recommended for the one performing the sacrifice to say اللهم تقبل منى along with Bismillah and Allahu Akbar at the time of slaughtering the animal, and our companions (the Shafi'is) say that it is also recommended to say اللهم منك و إليك اللهم تقبل مني along with Bismillah and Allahu Akbar.
Reference: Sharh al-Nawawi: 122/13.
② Sayyiduna Jabir bin Abdullah, may Allah be pleased with him, narrates that the Prophet, peace and blessings be upon him, slaughtered two castrated rams with two large horns on the day of Eid al-Adha, and when he turned them towards the Qiblah, he said these words:
إنى وجهت وجهي للذي فطر السموات والأرض على ملة إبراهيم حنيفا وما أنا من المشركين، إن صلاتي ونسكي و محياي ومماتي لله رب العالمين، لا شريك له وبذلك أمرت و أنا من المسلمين، اللهم منك ولك عن محمد و أمته بسم الله والله أكبر
Reference: Hasan: Sunan Abi Dawood: 2795. Sunan Ibn Majah: 3121. Mustadrak Hakim: 1/167. Sahih Ibn Khuzaymah: 2899.
Benefits:
It is prescribed and recommended to recite the mentioned words and say اللهم منك ولك عن فلان before slaughtering the sacrifice, and Imam Nawawi (may Allah have mercy on him) and Ibn Qudamah Hanbali (may Allah have mercy on him) have also considered the position of the majority of scholars as correct.
Reference: Sharh al-Nawawi, 122/13, Al-Mughni with Al-Sharh al-Kabir: 1128/11.
Also, after narrating the aforementioned hadiths, Ibn Qudamah Hanbali (may Allah have mercy on him) states that the hadiths of this chapter are such clear texts regarding the recommendation of this practice that there is no room for difference of opinion.
Reference: Al-Mughni with Al-Sharh al-Kabir: 118/11.
