As-Salamu alaikum Wa Rahmatullahi Wa Barakatuhu
Bismillahir Rahmanir Raheem,
A few years ago, I dreamt I was walking towards a mosque up on a hill, I took wudu‘ and when I went over to join the congregation prayer, it had already ended.I stood feeling disappointed and the dream ended there. I dreamt of this same dream for many nights. Then on one final night, I had the same dream again but with a different ending. The ending was that I finally got to join the congregation prayer and thereafter, the dream stopped recurring.
Shukran wa salaam.
Audhu billahi min ash-shaytan ir-rajim
Bismi-llāhi r-rahmāni r-rahīm
Wa `alaykumu s-salāmu wa rahmatu l-lāhi wa barakatuh
Mawlana Shaykh Hisham Kabbani said that entering a mosque in a dream means you are entering Ka`abatullah, as Allah (swt) said in Holy Qur’an that the masajid are the houses of Allah and that they belong to Allah. So entering a masjid means entering a reflection of the Ka`aba in that place.
Being not able to join the congregation prayers in the first dreams shows that you were in need to improve to reach a spiritual maqam.
And Allah knows best.