What Hadhrat Amina (May Allah be well pleased with her) saw
There is a Tradition in Musnad Imam Ahmed bin Hambal:
Translation: It is narrated on the authority of Hadhrat ‘Irbaadh bin Saariya (May Allah be well pleased with him), he says: The mother of the Holy Prophet (Sallallahu alaihi wa sallam) saw that at the time of the birth of the Holy Prophet (Sallallahu alaihi wa sallam) such a radiance issued forth that the palaces of Syria could be sen. (Musnad Imam Ahmed bin Hambal, Hadith No. 17615)
Why all these preparations? Because that Master is coming for whom everyone was waiting. He is the One, the glad tidings of whose arrival were given by the Prophets. He is the One, to be in whose Ummah was the wish of Hadhrat Moosa (May peace be upon him).