Narrated Jabir: We used to grow beard long except during the Hajj or Umrah. Abu Dawud said: Istihdad means to shave the pubes.
Explanation & Benefits
Shaykh Umar Farooq Saeedi
Benefits and Issues:
That is, during Hajj and ‘Umrah we used to trim a little, but on other occasions we did not do so. However, this narration itself is not authentic.
Therefore, even on the occasion of Hajj and ‘Umrah, trimming the beard is not permissible.
Source: Sunan Abu Dawood – Commentary by Shaykh Umar Farooq Saeedi, Page: 4201