Is it Islamically permissible to say "Allahu wakbar" instead of "Allahu akbar"?

The jurists differed on the ruling concerning someone who substitutes a 'waw' (و) for the hamza (ء) in "Allahu Akbar" (saying: Allahu Wakbar) in prayer and the adhan. There are two opinions:

The first: That it is correct and sufficient, because linguistically, substituting a 'waw' for the hamza in this case is permissible. This is the view chosen by Ibn Juzayy, Al-Qarafi, and Ibn Uthaymeen.

The second: That it is invalid and insufficient. This is the fatwa given by Al-Qaffal, Al-Ramli, and Al-Adawi.