Musnad Abi Ya'la 1685 — the Messenger of Allah ﷺ ordered the digging

It is narrated from Sayyiduna al-Bara' bin Azib (may Allah be pleased with him) that the Messenger of Allah (peace and blessings be upon him) ordered the digging of the Trench. He said: A hard rock appeared before us on which the pickaxes made no impression. The Companions complained of this to the Prophet (peace and blessings be upon him), so he (peace and blessings be upon him) took up the pickaxe. The narrator said: I think (he also said that) he (peace and blessings be upon him) put his cloak aside (for ease), said 'Bismillah' (In the name of Allah) and struck a blow, which broke off a third of the rock. Then he (peace and blessings be upon him) said: "'Allahu akbar' (Allah is the Greatest)! I have been given the keys of Syria (al-Sham), and I am seeing its red palaces from this very place of mine right now." Then he (peace and blessings be upon him) again said 'Bismillah' (In the name of Allah) and struck a second blow, and another third of the rock broke off, and he (peace and blessings be upon him) said: "'Allahu akbar' (Allah is the Greatest)! I have been given the keys of Persia. By Allah, I am seeing al-Mada'in and its white palace from this very place." Then he (peace and blessings be upon him) said 'Bismillah' (In the name of Allah) and struck a third blow, and the rest of the rock was shattered, and he (peace and blessings be upon him) said: "'Allahu akbar' (Allah is the Greatest)! I have been given the keys of Yemen. By Allah, I am seeing the keys (the gates of conquest) of San'a' from this very place of mine right now."