بُلُوغُ الْمَرَامِ
Bulugh al-Maram 344
The Book of Prayer
وَعَنْ خَالِدِ بْنِ مَعْدَانَ - رضى الله عنه - قَالَ : { فُضِّلَتْ سُورَةُ اَلْحَجِّ بِسَجْدَتَيْنِ } . رَوَاهُ أَبُو دَاوُدَ فِي اَلْمَرَاسِيلِ . [1]
Narrated Khalid bin Ma'dan (RA): Surat al-Hajj has been distinguished by two prostrations. [Abu Dawud reported it among al-Marasil (a broken chain after the Tabi'i)].
Sunnah.com reference: Book 2, Hadith 245