Sayyiduna Awf bin Malik (may Allah be pleased with him) narrates that the Prophet (peace and blessings be upon him) said: "On the night of the middle of Sha'ban (that is, the night of Bara'ah), Allah Almighty turns His attention to His creation and forgives all of them, except that He does not forgive the polytheist and the one who holds enmity (or resentment)."
Al-Bazzar recorded it; its chain contains Abd al-Rahman bin Ziyad bin An'um, whom Ahmad bin Salih declared thiqah (trustworthy) while the majority of the Imams declared him da'if (weak), and it contains Ibn Lahi'ah, who is layyin (soft, weak). The rest of its narrators are thiqat (trustworthy).
Hadith Referenceمجمع الزوائد ومنبع الفوائد / كتاب الأدب / 12959