Hadithcore
Sunan Abi Dawud, 686
sahih· Al-Albani

'Ata said:

The back of the saddle is (about) one cubit (in height) or more than that.

حَدَّثَنَا الْحَسَنُ بْنُ عَلِيٍّ، حَدَّثَنَا عَبْدُ الرَّزَّاقِ، عَنِ ابْنِ جُرَيْجٍ، عَنْ عَطَاءٍ، قَالَ آخِرَةُ الرَّحْلِ ذِرَاعٌ فَمَا فَوْقَهُ ‏.‏

References2 variants
In-Book Reference
Book 2, Hadith 296
English Reference
Book 2, Hadith 686