The meeting of Rasulullah (sallallahu ‘alaihi wasallam) with Nabi Musa (‘alaihis salaam) implied that just as Nabi Musa (‘alaihis salaam) went to wage jihaad against the Jabbaareen in Syria, and Allah Ta‘ala granted him victory over them, similarly, Rasulullah (sallallahu ‘alaihi wasallam) will enter the land of Syria to wage jihaad. Hence, Rasulullah (sallallahu ‘alaihi wasallam) went to Syria for the expedition of Tabook. There the leader of Dawmatul-Jundul requested Rasulullah (sallallahu ‘alaihi wasallam) for a truce on the promise of paying jizyah (security tax levied on non-Muslims living under Muslim rule). Rasulullah (sallallahu ‘alaihi wasallam) consented to the truce.
Similarly, just as Syria was conquered after Nabi Musa (‘alaihis salaam) at the hands of his successor, Hazrat Yusha’ (‘alaihis saalam), similarly, the entire region of Syria was conquered after the demise of Rasulullah (sallallahu ‘alaihi wasallam) at the hands of Hazrat ‘Umar (radhiyallahu ‘anhu).
In the seventh heaven, Rasulullah (sallallahu ‘alaihi wasallam) met Nabi Ebrahim (‘alaihis salaam). He saw him sitting with his back leaning on the Bayt-ul-Ma’moor. The Bayt-ul-Ma’moor is actually a musjid in the seventh heaven which is directly above the Ka’bah Shareef. Every day, seventy thousand angels make tawaaf of the Bayt-ul-Ma’moor (and they do not ever get a second chance to do so). Since Nabi Ebrahim (‘alaihis salaam) is the builder of the Ka’bah, he was honoured with this position (of sitting at the Bayt-ul-Ma’moor).
This final meeting indicated to the Hajjat-ul-Wadaa (the farewell Haj). It implied that Rasulullah (sallallahu ‘alaihi wasallam) would perform Haj of the Baytullah before his demise from this world. According to the interpreters of dreams, a vision of Nabi Ebrahim (‘alaihis salaam) in one’s dream is a glad tiding of an imminent Hajj.
(Extracted from Seeratul Mustafa 1/318-319)