Tafsir of Ash-Shu`ara' 26:63

فٲوحينا إلى موسى أن اضرب بعصاك البحر

Then We revealed to Musa (saying): "Strike the sea with your stick.''

فانفلق فكان كل فرق كالطود العظيم

And it parted, and each separate part became like huge mountain. meaning, like mighty mountains. This was the view of Ibn Mas`ud, Ibn Abbas, Muhammad bin Ka`b, Ad-Dahhak, Qatadah and others. Ata' Al-Khurasani said, "It refers to a pass between two mountains.'' Ibn Abbas said, "The sea divided into twelve paths, one for each of the tribes.'' As-Suddi added, "And in it there were windows through which they could see one another, and the water was erected like walls.'' Allah sent the wind to the sea bed to make it solid like the land. Allah says:

فاضرب لهم طريقا فى البحر يبسا ﻻ تخاف دركا وﻻ تخشى

and strike a dry path for them in the sea, fearing neither to be overtaken nor being afraid. (20:77) And here He says:

وأزلفنا ثم اﻻأخرين