Sayyidina Kaladah ibn Hanbal (RA) narrated: Safwan ibn Umayyah sent me to the Prophet (SAW) with a little milk, a young gazelle and some small cucumbers. The Prophet (SAW) was then in an upper part of the valley. I went to him but did not seek permission and did not offer salaam. So, he instructed me, “Go back and say, ‘assalaamu alikum, may I enter?” This was after Safwan had embraced Islam. Amr said, “Umayyah ibn Safwan told me of this hadith” and he did not say, “I heard it from Kaladah.”
[Abu Dawud 5176, Ahmed 15425]