What is the connection between the conquests of Yemen, Al-Sham, the Maghreb, and the Mashriq, and the rock struck by the Messenger of Allah, peace and blessings be upon him, at Al-Khandaq (the Battle of the Trench), as mentioned in Ibn Hisham's Sirah?

The rock itself has no relation to the conquests, but its appearance during the hardship that Muslims endured while digging the trench was among the proofs of the Prophet's prophethood, peace and blessings be upon him. Gabriel informed him of his nation's victory, and the Muslims rejoiced at that.