It is narrated from the Mother of the Believers, Sayyidah Aishah (may Allah be pleased with her), that "The Prophet (peace and blessings be upon him) used to give the salam after the even (two rak'ahs) of the witr, and also after the witr (its single rak'ah)."
Imam al-Tabarani (may Allah have mercy on him) said: "No one narrated this hadith from al-Wadin (may Allah have mercy on him) except Sadaqah (may Allah have mercy on him), and Muhammad bin Sulayman (may Allah have mercy on him) is alone in narrating it."