In one narration the wording is: Sayyiduna Ubayy (may Allah be pleased with him) said: The Prophet (peace and blessings be upon him) said to me: "I have been commanded to teach you the Qur'an."
(Allamah al-Haythami says:) I say: Al-Tirmidhi recorded it in abridged form. Al-Tabarani recorded it in al-Mu'jam al-Awsat with several chains, and the narrators of the first narration have been declared trustworthy.
Hadith Referenceمجمع الزوائد ومنبع الفوائد / كتاب المناقب / 15720