There is not in the heaven a space equivalent to four fingers, except that ..

There is not in the heaven a space equivalent to four fingers, except that an angel has prostrated his forehead to Allaah in it.

Hasan: Related by Ibn Maajah (no.4190) and at-Tirmidhee (2/51),who authenticated it, from Abu Dharr radiallaahu ‘anhu.

Source : Allaahu Akbar – Allaah is Greater