- When the intention precedes the opening Allahu Akbar by a long period:
It is not permissible for the intention to precede the opening Allahu Akbar by a long period. Ibn Rushd the Grandfather has quoted consensus on this.
- When the intention precedes the opening Allahu Akbar by a short period:
It is permissible for the intention to precede the opening Allahu Akbar by a short period. This is the position of the majority: the Hanafis, Malikis, and Hanbalis.
- Ruling of the intention following the opening Allahu Akbar:
It is not permissible for the intention to follow the opening Allahu Akbar by agreement of the four schools of jurisprudence. Saying the opening Allahu Akbar while standing
It is a condition for validity of the opening Allahu Akbar that it be said while standing. This is a matter of agreement among the four schools of jurisprudence. The Wording of the opening Allahu Akbar
Prayer is not initiated except by saying exactly Allahu Akbar during the opening Allahu Akbar. This is the position of the Malikis, Hanbalis, and the old position of al-Shafi`i. The majority of early Muslims held this position. It is also the position of Dawud al-Zahiri, and is the position chosen by Ibn al-Qayyim and Ibn `Uthaymin.

Secondly: Saying Allahu Akbar when changing position in prayer
Scholars differ regarding the ruling of saying Allahu Akbar when changing position [343] Saying Allahu Akbar when changing position in prayer: this refers to saying Allahu Akbar in prayer other than the opening Allahu Akbar. This includes saying Allahu Akbar for bowing and prostrating, rising from them, and rising from the first tashahhud. in prayer and are of two positions:
The first position: saying Allahu Akbar when changing position in prayer is one of the sunnahs of prayer, and is not mandatory. This is the position of the majority: the Hanafis, Malikis, and Shafi`is, as well as the majority of scholars of the Companions, Followers, and those after them.
The second position: saying Allahu Akbar when changing position in prayer is mandatory, and this is the position of the Hanbalis. Ishaq ibn Rahawayh and some of the Zahiris held this position. It is also the position chosen by Ibn Baz and Ibn `Uthaymin.