Narrated Zaid bin Thabit:
"We were with the Messenger of Allah (ﷺ) collecting the Qur'an on pieces of cloth, so the Messenger of Allah (ﷺ) said: 'Tuba is for Ash-Sham.' So we said: 'Why is that O Messenger of Allah?' He said: 'Because the angels of Ar-Rahman spread their wings over it.'" (DE)
English reference (DE): Vol. 1, Book 46, Hadith 3954 (DE)
Arabic reference (DE): Book 49, Hadith 4335 (DE)