Mishkat al-Masabih 3 Purification كتاب الطهارة 111

وَعَنِ ابْنِ عَبَّاسٍ قَالَ: قَالَ رَسُولُ اللَّهِ صَلَّى اللَّهُ عَلَيْهِ وَسَلَّمَ: «إِذَا تَوَضَّأْتَ فَخَلِّلْ بَيْنَ أَصَابِعِ يَدَيْكَ وَرِجْلَيْكَ» . رَوَاهُ التِّرْمِذِيُّ. وَرَوَى ابْنُ مَاجَهْ نَحْوَهُ وَقَالَ التِّرْمِذِيُّ: هَذَا حَدِيثٌ غَرِيب

Ibn ‘Abbas reported God’s messenger as saying, “When you perform ablution let the water run between your fingers and your toes.” Tirmidhi transmitted it and Ibn Majah transmitted something similar. Tirmidhi said that this is a gharib tradition.