This tradition has also been transmitted by Saeed through a different chain of narrators to the same effect. Ibn Bashshar narrated the tradition like that of Yahya bin Saeed. His version has: He uttered the salutation in a way that we could hear it.
Explanation & Benefits
Shaykh Umar Farooq Saeedi
1345. Commentary: Benefit: To end the prayer, even a single salutation (salam) is sufficient. In the night prayer (tahajjud), the Prophet (sallallahu alayhi wa sallam) used to act upon this.
Source: Sunan Abu Dawood – Commentary by Shaykh Umar Farooq Saeedi, Page: 1345