Musannaf Ibn Abi Shaybah 7642 — Perfuming the mosques with saffron

Al-Sha'bi said: "The Prophet (peace and blessings be upon him) saw phlegm that had fallen on the qiblah side of the mosque, so he scraped it off with his hand and called for perfume mixed with saffron and applied it." Amir said: "Applying saffron-based perfume in the mosques is a sunnah."