Musannaf Ibn Abi Shaybah 5004 — Sleeping in the mosque

Ata said: A man said to Sayyiduna Ibn Abbas (may Allah be pleased with them both): I slept in al-Masjid al-Haram and had a wet dream; so is it permissible to sleep in the mosque? He said: Making the mosque a place to spend the night or to take the midday nap is not permissible. However, resting for a while, or waiting for some matter, is permissible.