Isa bin Yonus bin Abi Ishaq عيسى بن يونس بن أبي إسحاق · Fasting (Kitab Al-Siyam)

I did not see any of our companions who abominated the use of collyrium by a man who fasting. Ibrahim would permit the man who was fasting to apply collyrium with aloes.

The Messenger of Allah (ﷺ) as saying: The most excellent fast after Ramadan is Allah's month al-Muharram, and the most excellent prayer after the prescribed prayer is the prayer during night.