Abu Juhayfa reported,

The Prophet ﷺ established a bond of brotherhood between Salman and Abu Darda. Salman once visited Abu Darda and noticed that Umm Darda was wearing shabby clothes.He asked her, "What is the matter with you?"She replied, "Your brother Abu Darda has no interest in this world."Then Abu Darda came and prepared food for him and said, "Eat."Salman said, "I am fasting."Abu Darda said, "I will not eat until you eat."So he ate. When night came, Abu Darda got up to pray.Salman said, "Sleep."So he slept. Then he got up again to pray, and Salman said, "Sleep."When it was the latter part of the night, Salman said, "Get up now."So they prayed together. Then Salman said to him, "Your Lord has a right over you, your own self has a right over you, and your family has a right over you. So give each one who has a right his due."Abu Darda then went to the Prophet ﷺ and mentioned what had happened.The Prophet ﷺ said, "Salman has spoken the truth."

Bukhari 1968

Sahih

حدثنا محمد بن بشار حدثنا جعفر بن عون حدثنا أبو العميس

عن عون بن أبي جحيفة عن أبيه قال

آخى النبي ﷺ بين سلمان وأبي الدرداء فزار سلمان أبا الدرداء فرأى أم الدرداء متبذلة فقال لها ما شأنك قالت أخوك أبو الدرداء ليس له حاجة في الدنيا فجاء أبو الدرداء فصنع له طعاما فقال كل قال فإني صائم قال ما أنا بآكل حتى تأكل قال فأكل فلما كان الليل ذهب أبو الدرداء يقوم قال نم فنام ثم ذهب يقوم فقال نم فلما كان من آخر الليل قال سلمان قم الآن فصليا فقال له سلمان إن لربك عليك حقا ولنفسك عليك حقا ولأهلك عليك حقا فأعط كل ذي حق حقه فأتى النبي ﷺ فذكر ذلك له فقال النبي ﷺ صدق سلمان

البخاري 1968صحيح
Contents
Reference
Commentary
Ayat
Collection
Sahih Bukhari
Book
Fasting
Chapter
One who swears upon his brother to break his voluntary fast and does not consider making it up obligatory for him, if that is more suitable for him
Numbering
Darussalam 1968
Bukhari 1968