English Translation
Narrated 'Abdullah bin Malik bin Buhaina Al-Asdi: When the Prophet prostrated, he used to keep his arms so widely apart that we used to see his armpits. (The subnarrator, Ibn Bukair said, "The whiteness of his armpits.")
This hadith is from Sahih al-Bukhari, the most rigorously authenticated collection in Islamic scholarship. No editorial opinion is added.