Is it possible to know the narrator of the hadith: "Whoever spends the night upon witr, spends the night forgiven," and "Indeed, Allah is Witr (One) and loves witr"?

The hadith: "Indeed, Allah is Witr (One, Unique), and He loves witr (odd numbers)" is authentic. It was narrated by Ahmad, Abu Dawud, An-Nasa'i, and others from Ali (may Allah be pleased with him) with the wording: "O people of the Qur'an, perform witr prayer, for indeed Allah is Witr and He loves witr."

As for the hadith: "Whoever sleeps having prayed witr, sleeps forgiven," it has not been reported in the books of Sunnah. What has been reported in the authentic collections (Sahih) and Sunan books regarding the encouragement of witr is sufficient.