Re: which surah
The donkey is mentioned in the Qur'an for four times, in Surah Baqarah ayah 259,** then Surah Jumuah ayah 5:**
The likeness of those who were entrusted with the Tawrah, but did not carry it, is as the likeness of a donkey(Himar) which carries huge burdens of books. How bad is the example of people who deny the Ayat of Allah. And Allah does not guide the people who are wrongdoers.)
Surah Luqmaan ayah 19:
(19. "And be moderate in your walking, and lower your voice. Verily, the harshest of all voices is the braying of the asses.'')(Hamir)
Surah Nahl Ayah 8:
And (He has created) horses, mules and donkeys(Hamir) for you to ride, and as an adornment. And He creates (other) things of which you have no knowledge.)