أَيَّتُهَا

A word in the Arabic language will either be 1) a verb or 2) a noun or 3) a particleأَيَّتُهَا is a particle

Ayyu. Ayyatu particle prefixed to Ha before the vocative

مَعْرِفَةٌمُفْرَدٌمُؤَنَّثٌأَيَّتُهَاOأَيَّتُهَا is أَيَّتُ prefixed to هَا before يَآ (the vocative)حَرْفٌحَرْفُ التَّنْبِيهِ
DefiniteSingularFeminineRootParticleParticle of attention
Surah/Below are the 2 verses in the holy Quran containing the prefixed particleأَيَّتُهَا
Verse
12-70
89-27O the self in rest and satisfactionيَآ أَيَّتُهَا النَّفْسُ المُطْمَئِنَّةُ