Assalamalaium, Theres a story about one of the companion of Prophet SAW, Jarir ibn Al Bajali about being a sincere well wisher for every muslim..the story is that once he sends his servant to buy a horse..The servant makes a deal for 300 dhs but he ends up purchasing it for 800 dhs because he realized that the seller had undervalued and he wanted to be fair and his sincere to him.Could you please provide a reference for this story/ confirm if this is a true story.

All perfect praise be to Allaah, the Lord of the Worlds. I testify that there is none worthy of worship except Allaah, and that Muhammad, sallallaahu ‘alayhi wa sallam, is His Slave and Messenger.

This story was mentioned by An-Nawawi in his commentary on Saheeh Muslim as he said: “In regard to the Hadeeth about Jareer it is a virtue and a noble deed from him, which was reported by Al-Haafith Abu Al-Qaasim At-Tabaraani with its chain of narrators. Its summary is that Jareer ordered his servant to buy a horse for him, so he bought one for him for 300 Dirhams, and he came with the horse along with its owner so that Jareer would pay him its price. So, Jareer told the owner of the horse: “Your horse is worth more than 300 Dirhams…” to the end of the story which is also mentioned in Fat-h Al-Baari by Ibn Hajar and in other books.

Allaah Knows best.