Barakat Mohammed

At the entry of Essaouira there is a big sandcoloured sculpture. We can read arabic letters. What is their meaning?
First.
What is the origin of this towns name?
There are many different explanations.
In the 7th century, the Phoenicians stopped over in the Island of Mogador and they named it Migdal , Migdol ("watchtower"). The Romans later founded a Tyrian purple factory there which gave it the name "the Purple Islands" ( d’iles Purpuraires, l’ile de Mogador) , just off the coast from Essaouira.
The muslim saint Sidi Mogdoul was buried here in the middle ages and his name is important to this place. In berber (amazigh) language Amagdoul (the well garded). The portugeese (called it Mogdura, the spanish Mogadour and the french Mogador.
There are more linguistic ideas about the root of letters as GDR and origin of Mogador.
(Souss.com,forum en francais)
(Mogador : Son étymologie judéo berbère, Omar Lakhdar (Essaouira, Maroc)

The meaning of the inscription
On the south wall of the east Sqala Port tower , there is an carved inscription in sandstone. It is arabic calligraphy and reads “Barakat Mohammed”. The inscription means " blessing of Mohammed – prophet of Islam". It is dating from 18th century at the foundation of the town by the sultan Sidi Mohammed Ben Abdellah al-Qatib (c. 1710-1790) ( محمد الثالث بن عبد الله الخطيب‎ ) calling about divine protection of the town. He let build a fortress originally called Souira ("the small fortress"). Later the name was Es-Saouira ("the beautifully made, the picture") Today this town is called Essaouira... الصويرة
Other older names in berber are Tasurt and Amgader.
Medina of Essaouira (formerly Mogador) was added to UNESCO World Heritage List in 2001