The Takbir of Ihram.

The Shaykh : Then the person says takbir after facing the qiblah. He says takbir and says: Allahu Akbar. This takbir is called by the scholars the Takbir of Ihram. It is a pillar of the prayer, and the prayer is not valid without it. So if he forgets to say takbir and then starts reciting al-Fatihah and completes his prayer, what is the ruling? He must repeat the prayer. Why? Because his prayer was not valid, as it is necessary for the validity of the prayer that the person says Allahu Akbar. Now, if he says: Allah Ajal, does this suffice for Allahu Akbar? No, he must say Allahu Akbar. He should not say: Allah Akbar with a long ba, because if he says Allah Akbar, the meaning changes, and it no longer means that Allah is greater than everything. The word Akbar has another meaning that is not befitting Allah (Mighty and Majestic). Now, if he says Allah Wakbar, does this suffice or not?
The student: It does not suffice.

The Shaykh : It suffices, because in the Arabic language, it is permissible to change the hamza to a waw if it is preceded by a dammah. So here, saying Allah Wakbar suffices. However, the hamza is preferable, because the waw is a substitute, and returning to the original is preferable to returning to the substitute. If he says A-Allahu Akbar, does this not suffice?
The student: No.

The Shaykh : Why? Because this changes the meaning, as saying A-Allahu Akbar implies a question, like the saying of Allah the Exalted: If the meaning is disrupted, then it does not suffice.