The believers rejoice at Allah's victory, raising their voices with takbir (Allahu Akbar “Allah is the greatest”) as an expression of genuine happiness for Allah’s support of those striving in His cause. Various evidence confirms its permissibility, even recommending it, based on the actions of the Prophet ﷺ and his noble companions. Some examples include:

1. The Prophet's Takbir Upon the Death of Abu Jahl in Badr:
   The Prophet ﷺ said takbir when he learned about the killing of Abu Jahl during the Battle of Badr. Ahmad narrated in his Musnad from Ibn Mas'ud, who said: “I came to the Prophet ﷺ on the day of Badr and said, 'I have killed Abu Jahl.' He asked, 'By God than Whom there is no god' I replied, 'By Allah, God than Whom there is no god.' He repeated it three times, then said: 'Allahu Akbar! Praise be to Allah who has fulfilled His slave and defeated the confederates alone. Lead me to him.' We went to see him, and when the Prophet ﷺ saw his body, he said: 'This is the Pharaoh of this nation.'”
2. The Prophet’s Takbir Upon Victory in Khaybar:
   The Prophet ﷺ announced his victory in the Battle of Khaybar by raising his voice in takbir out of joy and happiness. Al-Bukhari and Muslim narrated from Anas: “The Messenger of Allah (ﷺ) raided Khaibar. One morning we offered prayers in the darkness of early dawn (near Khaibar). Then the Messenger of Allah (ﷺ) mounted (his horse). Abu Talha mounted his and I mounted behind Abu Talha on the same horse. The Prophet of Allah (ﷺ) rode through the streets of Khaibar and (I rode so close to him) that my knee touched the thigh of the Prophet of Allah (ﷺ). The wrapper got aside from his thigh, and I could see its whiteness. When he entered the town, he said: God is Great. Khaibar shall face destruction. When we descend in the city-square of a people, it is a bad day for them who have been warned (and have not taken heed).”
3. The Prophet’s Takbir Rejoicing Over His Companions’ Victory Over Shaytan’s Whisperings:
   Abu Dawud narrated in his Sunan from Ibn Abbas: “A man came to the Prophet (ﷺ) and said: Messenger of Allah! one of us has thoughts of such nature that he would rather be reduced to charcoal than speak about them. He said: Allah is Most Great, Allah is Most Great, Allah is Most Great. Praise be to Allah Who has reduced the guile of the devil to evil prompting.”
   This hadith illustrates that some companions had some Shaytan’s whisperings but refrained from discussing them due to their strong faith, which delighted the Prophet ﷺ.
4. The Prophet’s Takbir Upon the Birth of Abdullah ibn Abi Talhah:
   Ahmad narrated in his Musnad from Anas ibn Malik: “When Um Sulaim gave birth to a child, I carried him to the Prophet ﷺ and said, ‘O Messenger of Allah, Um Sulaim has given birth to a boy.’ He said, 'Allahu Akbar, what did she give birth to?' I replied, 'A boy.' He said, 'Praise be to Allah.' He then said, 'Bring him to me.' I handed him to the Prophet ﷺ, and he rubbed his palate with dates (tahnik).”
5. The Companions’ Takbir Upon the Prophet’s Glad Tidings of Paradise:
   Al-Bukhari narrated from Abdullah ibn Mas'ud saying, “We were with the Prophet ﷺ, and he said: By Him in Whose Hands my life is, hope that you will be one-fourth of the people of Paradise. We shouted: Allahu Akbar! He added: I hope that you will be one-third of the people of Paradise. We shouted: Allahu Akbar! He said: I hope that you will be half of the people of Paradise. We shouted: Allahu Akbar!”
6. The Prophet’s Reception in Madinah During His Migration:
   Ahmad narrated in his Musnad from Al-Bara' ibn ‘Azib regarding the migration: “Abu Bakr said: The The Messenger of Allah (ﷺ) and I continued on our way until we came to Madinah, where the people met him. They came out on the road and on the roofs, and a lot of servants and children crowded the road saying: Allahu Akbar, the Messenger of Allah (ﷺ) has come, Muhammad has come.”
7. Haram ibn Milhan’s Takbir Upon Being Fatally Stabbed:
   Al-Bukhari narrated in his Sahih from Anas: “The Prophet (ﷺ) sent seventy men from the tribe of Bani Salim to the tribe of Bani Amir. When they reached there, my maternal uncle (Haram ibn Milhan) said to them, ‘I will go ahead of you, and if they allow me to convey the message of Allah's Messenger (ﷺ) (it will be all right); otherwise you will remain close to me.’ So he went ahead of them and the pagans granted him security But while he was reporting the message of the Prophet (ﷺ), they beckoned to one of their men who stabbed him to death. My maternal uncle said, ‘Allah is Greater! By the Lord of the Ka`ba, I am successful.’”
8. A Companion’s Takbir Upon Learning About Flexibility in Religious Matters:
   Muslim in his Sahih and Abu Dawud (with the latter’s wording) narrated from Ghudayf ibn al-Harith: I asked Aisha: Have you seen the Messenger of Allah (ﷺ) washing (because of defilement) at the beginning of the night or at the end? She replied: Sometimes he would take a bath at the beginning of the night and sometimes at the end. Thereupon I exclaimed: Allah is most Great. All Praise be to Allah Who made this matter accommodative. I again asked her: What do you think, did the Messenger of Allah (ﷺ) say the witr prayer (additional prayer after obligatory prayer at night) in the beginning of the night or at the end? She replied: Sometimes he would say the witr prayer at the beginning of the night and sometimes at the end. I exclaimed: Allah is most Great. All praise be to Allah Who made the matter accommodative. Again I asked her: What do you think, did the Messenger of Allah (ﷺ) recite the Qur'an (in the prayer) loudly or softly? She replied: Sometimes he would recite loudly and sometimes softly. I exclaimed: Allah is most Great. All praise be to Allah Who made the matter flexible.
9. Uthman’s Takbir When Besieged, Bearing Testimony to the Prophet’s Glad Tidings of His Martyrdom:
   At-Tirmidhi and An-Nasa'i (authenticated by Al-Albani) narrated from Thumamah bin Hazn Al-Qushairi: “I was present at the house when 'Uthman looked out over them and said: 'I adjure you by Allah and by Islam, are you aware that when the Messenger of Allah was atop Thabir -the Thabir in Makkah- and with him were Abu Bakr, 'Umar and myself, the mountain shook, and the Messenger of Allah kicked it with his foot and said: Be still, Thabir, for upon you are a Prophet, a Siddiq and two martyrs?' They said: 'By Allah, yes.' He said: 'Allahu Akbar! They have testified for me, by the Lord of the Ka'bah' -i.e., that I am a martyr.”

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