Bukhari

Hadith Commentary:
Since the debtor was extremely trustworthy and a believer who fulfilled his promises, Allah accepted his supplication, and both creditors received their trust and the written amount in safety. Such men of truth are rare today; these are the very people about whom it has been said that destinies are changed by the gaze of a believing man.
May Allah make us among them. Ameen.

Hadith Commentary:
(1)
Imam Bukhari rahimahullah’s point of inference is this phrase:
"From so-and-so to so-and-so," meaning that the letter should begin with the name of the sender, and then the name of the addressee to whom the letter is written should be mentioned. Thus, it is narrated in the hadith that Abu Al-‘Ala bin Al-Hadrami radi Allahu anhu wrote a letter to the Messenger of Allah sallallahu alayhi wa sallam, and he began the letter with his own name.
(Sunan Abi Dawud, Al-Adab, Hadith: 5135) (2)
The opposite is also established from Zayd bin Thabit radi Allahu anhu, as when he wrote a letter to our master Amir Mu‘awiyah radi Allahu anhu, he would begin with our master Amir’s name:
"To the servant of Allah, Mu‘awiyah, Commander of the Believers, from Zayd bin Thabit." (Al-Adab Al-Mufrad, Hadith: 1122)
Similarly, when Abdullah bin ‘Umar radi Allahu anhu wrote to ‘Abdul Malik, he would adopt the following style:
"In the name of Allah, the Most Gracious, the Most Merciful. To ‘Abdul Malik, Commander of the Believers, from Abdullah bin ‘Umar."
(3)
Hafiz Ibn Hajar rahimahullah has written, quoting Imam Muhallab, that when writing a letter, a person should begin with his own name.
(Fath al-Bari: 11/58)
This style was adopted in all the letters of the Messenger of Allah sallallahu alayhi wa sallam.
And Allah knows best.