بُلُوغُ الْمَرَامِ
Bulugh al-Maram 668
Fasting
وَعَنْ عَائِشَةَ رَضِيَ اَللَّهُ عَنْهَا, { أَنَّ اَلنَّبِيَّ - صلى الله عليه وسلم -اِكْتَحَلَ فِي رَمَضَانَ, وَهُوَ صَائِمٌ } رَوَاهُ اِبْنُ مَاجَهْ بِإِسْنَادٍ ضَعِيفٍ [1] . قَالَ اَلتِّرْمِذِيُّ: لَا يَصِحُّ فِيهِ شَيْءٌ [2] .
'A’isha (RAA) narrated, The Messenger of Allah (ﷺ) applied kohl to his eyes while he was fasting.’ Related by Ibn Majah with a weak chain of narrators. According to At-Tirmidhi, nothing authentic has been related from the Prophet (ﷺ) concerning this issue, i.e. applying kohl, eye drops etc. to the eye while fasting.
Arabic/English book reference: Book 5, Hadith 689