Abu Dawud said: In the word yaghulla the letter ya has a short vowel a.
In-book : Book 32, Hadith 3
English translation : Book 31, Hadith 3960
32. 'Dialects and Readings of the Qur''an (Kitab Al-Huruf Wa Al-Qira''at)'
باب التَّخَلِّي عِنْدَ قَضَاءِ الْحَاجَةِ