Short answer
It is the Eid takbir said once after every fard prayer from Fajr on 9 Dhul Hijjah to Asr on 13 Dhul Hijjah, 23 prayers in all. In the Hanafi school it is wajib: men say it aloud, women quietly. The words are Allahu akbar, Allahu akbar, la ilaha illallah, wallahu akbar, Allahu akbar, wa lillahil hamd.
Takbir al-Tashreeq is wajib once after each fard prayer from Fajr of the day of Arafah to Asr of the 13th, on the fatwa view of Abu Yusuf and Muhammad. It applies to men and women, residents and travellers, and to someone praying alone. It is said straight after the salam; if he leaves the mosque or speaks, it lapses.
Other madhhabs
- Shafi'i
- It is sunnah, said after every prayer including voluntary ones, from Fajr of the day of Arafah to Asr of the 13th, starting with three takbirs.
- Maliki
- It is mustahabb after fifteen fard prayers, from Dhuhr on the day of Eid to Fajr of the fourth day.
- Hanbali
- It is sunnah after fard prayers, especially in congregation, from Fajr of the day of Arafah to Asr of the 13th.
Explanation
The Quran says "remember Allah during numbered days", which the scholars explain as the days of tashreeq, and the Prophet ﷺ called them days of eating, drinking and remembering Allah. The takbir after the prayers is the main form of this remembrance.
The words in the Hanafi school: Allahu akbar, Allahu akbar, la ilaha illallahu wallahu akbar, Allahu akbar wa lillahil hamd (Allah is the Greatest, Allah is the Greatest, there is no god but Allah, and Allah is the Greatest, Allah is the Greatest, and to Allah belongs all praise).
- Start: after Fajr on 9 Dhul Hijjah, the day of Arafah.
- End: after Asr on 13 Dhul Hijjah. That makes 23 prayers.
- How many times: once is wajib. Three times is a common practice and is fine.
- Men and women: men aloud, women softly.
- Forgot: say it as soon as you remember, if you have not left the place or spoken. Missed qada prayers of these days, made up within the same days, also have the takbir.
- Eid prayer: it is not wajib after the Eid prayer itself, but it is good to say it on the way to the Eid prayer and on the way back.
For how the Eid prayer is done, see how to pray Eid salah, and for this year's dates, Eid dates.
The evidence
Quran, Surah Al-Baqara 2:203
۞ وَٱذْكُرُوا۟ ٱللَّهَ فِىٓ أَيَّامٍۢ مَّعْدُودَٰتٍۢ ۚ فَمَن تَعَجَّلَ فِى يَوْمَيْنِ فَلَآ إِثْمَ عَلَيْهِ وَمَن تَأَخَّرَ فَلَآ إِثْمَ عَلَيْهِ ۚ لِمَنِ ٱتَّقَىٰ ۗ وَٱتَّقُوا۟ ٱللَّهَ وَٱعْلَمُوٓا۟ أَنَّكُمْ إِلَيْهِ تُحْشَرُونَ ﴿٢٠٣﴾
And remember Allah during [specific] numbered days. Then whoever hastens [his departure] in two days - there is no sin upon him; and whoever delays [until the third] - there is no sin upon him - for him who fears Allah. And fear Allah and know that unto Him you will be gathered.
The command to remember Allah on the days of tashreeq.
Sahih Muslim 1141
Sahih... أيام التشريق أيام أكل وشرب ...
"The days of tashreeq are days of eating and drinking, and in another narration, and of remembering Allah."
The days of tashreeq are days of dhikr.
Where the ruling is recorded
- al-Hidaya, Bab Salat al-Idayn, section on the takbir of tashreeq. When the takbir starts and ends, and its wording.
- Radd al-Muhtar (Ibn Abidin), Bab al-Idayn, takbir al-tashreeq. The fatwa follows Abu Yusuf and Muhammad on its duration and on who says it.
- Minhaj al-Talibin (Nawawi), Kitab Salat al-Idayn. The Shafi'i timing and the three opening takbirs.
This answer is pending review by the scholars on our team. Quran translation by Sahih International. Hadith Arabic from the standard editions of the six books and the Muwatta, with gradings as recorded there; the English is our own rendering. Spotted a mistake? Tell us.