Mishkat al-Masabih 30 Fine Qualities كتاب المناقب 209

وَعَنْ مُوسَى بْنِ طَلْحَةَ قَالَ: مَا رَأَيْتُ أَحَدًا أَفْصَحَ مِنْ عَائِشَةَ. رَوَاهُ التِّرْمِذِيُّ وَقَالَ: هَذَا حَدِيثٌ حَسَنٌ صَحِيحٌ غَرِيبٌ

Musa b. Talha said he had seen no one whose speech was more chaste than `A’isha’s. Tirmidhi transmitted it, saying this is a hasan sahih gharib tradition.