Source: Tafsir al-Ahlam al-Kabir (Ibn Sirin)
The mosque in a dream is a knowledgeable man or a just ruler. Entering the mosque indicates security, knowledge, and guidance. Building a mosque indicates enjoining good and forbidding evil.
Source: Ta'tir al-Anam fi Ta'bir al-Manam (Al-Nabulsi)
The mosque indicates justice, judgment, and the market. Whoever sees his house turn into a mosque will gain honor and high status. Whoever sees a mosque demolished, a scholar or ruler has died in that place.
Source: Al-Isharat fi Ilm al-Ibarat (Ibn Shahin)
The mosque is interpreted as the king, the scholar, or the righteous wife. Praying in it is the fulfillment of a need. Sleeping in it indicates trust in God.