The one who is put first in a letter Al-Adab Al-Mufrad 1126
Arabic hadith text
وَعَنِ ابْنِ عَوْنٍ، عَنْ أَنَسِ بْنِ سِيرِينَ قَالَ: كَتَبَ رَجُلٌ بَيْنَ يَدَيِ ابْنِ عُمَرَ: بِسْمِ اللهِ الرَّحْمَنِ الرَّحِيمِ، لِفُلاَنٍ، فَنَهَاهُ ابْنُ عُمَرَ وَقَالَ: قُلْ: بِسْمِ اللهِ، هُوَ لَهُ.
Translation
Anas ibn Sirin said, "A man wrote in the presence of Ibn 'Umar,'In the Name of Allah, the All-Merciful, Most Merciful, to so-and-so.'Ibn 'Umar forbade him and said, 'Say
'In the Name of Allah. It is forHim.'"