Writing on the Ground
Interpreters mention that whoever sees themselves writing on the ground in a dream, it may indicate that they are an atheist. There is also a story about Al-Hasan Al-Basri who saw himself writing the Quran on a piece of cloth; Ibn Sirin interpreted this by warning him against interpreting the Quran with personal opinion, indicating that his dream points to that.
Per Ibn Sirin's Muntakhab al-Kalam fi Tafsir al-Ahlam