Reciting Surah Al-Asr when you part from a companion is a Sunnah

Whenever the Sahaba met and seperated they would recite Surah Al-Asr.

Surah Al-Asr is a short and comprehensive chapter of The Quran,which reminds us that the saved group of human beings are those who:

  1. Believe in Islam
  2. Do righteous deeds
  3. Call people towards the truth(i.e. Islam and whatever relates to it)
  4. Bear patiently (in hardship, ease and worship)

It was narrated that Abu Madeenah al-Darimi said:

When two men among the companions of the Prophet (ﷺ) met, they did not part until one of them recited to the other:

1. “By al‑‘Asr (the time).

2. Verily, man is in loss” [i.e., Surah al-‘Asr],

then one would say Salam to (greet) the other.

Narrated by Abu Dawood (no. 417),classed as saheeh by al-Albani in al-Silsilah al-Saheehah (2648).

See- Reciting Surah Al-Asr before leaving a gathering.