Is allowed to read Quran from mobile during praying in case the mobile is not activated I mean there is no network or sim card.

Praise be to Allah, the Lord of the Worlds; and may His blessings and peace be upon our Prophet Muhammad and upon all his Family and Companions.

The ruling of reading Qur'an from the mobile is the same as the ruling of reading the Qur'an from the Qur'an  (Mus-haf) itself. The mobile might even be considered more suitable in such a matter if it does not cause any other disturbance that is contrary to the nature of a Prayer.

Scholars of Islam differ concerning the ruling of reading the Qur'an from its Book in prayer. The Hambali and Shafi'e are of the view that it is lawful to read the Qur'an from the Mus-haf in all prayers (obligatory as well as supererogatory ones).

Their evidence is the Hadith reported by Al-Baihaqi in his Sunan that Aisha said "that she used to pray behind her servant Thakwan (as Imam) while he read from the Mus-haf and that was in Ramadan." Al-Bukhari mentioned this Hadith in his commentary.

Imam Ahmed said: "There is no objection that the Imam leads people in Taraweeh while reading from a Mus-haf." Someone asked: "and the obligatory prayers?" He replied: "I did not hear anything objecting to that."

However some scholars are of the opinion that it is not acceptable. Abu Hanifa even considered the prayer performed while reading from the Mus-haf, invalid. But according to his two companions it is only dislikable to do so.

Anyway, we think it is more appropriate to refrain from reading from the Mus-haf in obligatory prayers and to limit that to supererogatory prayers when necessary like Taraweeh and night prayers.

Allah knows best.