The Messenger (PBUH) ordered the manufacture of the catapult and the armored car. Al-Bayhaqi mentioned in the Sunan that Abu ‘Ubaydah (ra) said:. “Then the Messenger of Allah put siege around Tai’f, and erected the catapult against them for seventeen days”. Abu Dawud reported in the al-Marasil from Makhul “That the Prophet (PBUH) erected the catapult against the people of Ta’if”. Al-San’ani said in Subul al-Salam that its narrators are reliable. The author of the Sirah Halabiyyah said: “It is Salman al- Farsi (ra) that directed him to do this. He said, ‘In Persia we used to erect the catapults on top of the castles and hit our enemy.’ It is said that Salman (ra) made it with his own hands”. Ibn Al-Qayyim reported from Sa’d ibn Al-Mu’adh and Ibn Hisham in Ibn Ishaq’s Sirah: ..

“Till the day of shatter took place near the wall of Ta’if, few people of the companions of the Messenger of Allah (PBUH) moved under an armored car and entered the wall of Ta’if so as to burn it. Thaqeef sent against them rods of iron heated with fire, so they got out of it. Thaqeef then hit them with arrows and killed some of them”. Thus, Salman was the one that advised them about the use of the catapult, and it is said that he made it with his own hands. .

This must have been done by the command of the Messenger (PBUH). You can find in the seerah, the saying of al-Halabiyyah: “he directed him to it”. This means he advised the Messenger (PBUH) of that. It is understood from these reports that military industries are of the responsibility of the Khalifah, and he seeks the help of whomever he likes to undertake them and organise them. The industry does need an amir, rather than a manager. Salman was not an amir to the military industries, rather a manager to the catapult industry; and he may have worked with his own hands. Establishing the military industries is compulsory, because of His (PBUH) saying:. “Make ready for them all you can of (armed) force and of horses tethered, that thereby you may dismay (place terror in) the enemy of Allah and your enemy, and others beside them whom you know not. Allah knows them.” [].