يَا زَيْدَاهْ! / وَا زَيْدَاهْ!
Translation: Alas, Zayd!
يَا / وَا: lamentation particles; wā is specific to lamentation.
زَيْدَ: lamented name; final fatḥa before the lamentation alif is a phonetic adjustment.
ا: lamentation alif.
هْ: pausal hāʾ.
This is not an ordinary summons; the final alif and hāʾ belong to the lamentation form.