Assalaamu alaykum. I know that when starting the prayer by saying Allaahu Akbar, you must not leave a gap between saying Allaahu and Akbar, but if I left a gap accidentally in a transitional Takbeer (saying Allaahu Akbar), would that be considered an incorrect pronunciation? Would I need to repeat it in a correct way? Additionally, I asked a question previously about recording myself on video, but I did not receive any answer.

All perfect praise be to Allaah, The Lord of the worlds. I testify that there is none worthy of worship except Allaah and that Muhammad, sallallaahu ‘alayhi wa sallam, is His slave and Messenger. 

A group of jurists stated that it is prohibited to leave a gap between the two words of the Takbeer (Allaahu and Akbar) and that leaving a long gap invalidates the prayer if that happened in Takbeerat A-Ihraam (opening the prayer by saying Allaahu Akbar). Hence, it cannot be said that any gap invalidates the prayer; rather, only a long gap invalidates it. An-Nafraawi wrote:

“Know that the Takbeer must be pronounced in that order (first Allaahu and then Akbar). Beware of extending the ‘hamzah’ at the beginning of ‘Allaahu,’ making it sound like a question; extending the vowel in Akbar (by saying Akbaaaar); doubling the ‘r’ sound at the end of Akbar; leaving a long gap between Allaahu and Akbar; extending the ‘hu’ sound at the end of Allaahu (Allaahooo Akbar); or adding the letter “waaw” to the ‘hamzah’ of Akbar (Allaahu wa-Akbar); all these mistakes invalidate the Takbeer.” [Sharh Ar-Risaalah]

Thus, you come to know that there is no harm in leaving a short gap between the two words of Takbeer regardless of whether that be in Takbeerat Al-Ihraam or in the transitional Takbeer. If the person leaves a long gap in the transitional Takbeer, then that does not invalidate the prayer because, according to the majority of the scholars, the transitional Takbeer is an act of the Sunnah. If this happens while he is still in the place of Takbeer in the prayer, then he may repeat it, just like the person who forgets to make Takbeer or who makes a mistake by making Tasmee’ (saying ‘Sami‘a Allaahu liman Hamidah’ instead of Takbeer. Scholars said that he repeats it if he remembers it while in the same position of the prayer (before moving to the next position of the prayer).

Al-Fawaakih Ad-Dawaani ‘ala Risaalat Ibn Abi Zayd Al-Qayrawaani (1/221) reads, “If the praying person forgetfully missed reciting a Takbeer other than a Takbeer in the ‘Eed prayer and Takbeerat Al-Ihraam or he missed saying ‘Sami‘a Allaahu liman Hamidah’ once, then he should say it (as long as he is still in the relevant position of the prayer).”

Allaah knows best.