Mu`adh ibn Jabal (RA) narrated that the Prophet (peace be upon him said):
“Allah looks at His creation in the night of mid-Sha`ban and He forgives all His creation except for a mushrik (idolater) and a mushahin (one bent on hatred)”.
[Sahih Ibn Hibban]
This hadith is related in Sahih ibn Hibban and is classed as such by two of our contemporary Hadith scholars, Sheikh Shu`ayb Arna’ut and the late Sheikh Albani.
Haythami said that Tabarani also narrated it in his Kabir and Awsat with chains containing only trustworthy narrators, that is: sound (sahih) chains; Ibn Khuzayma included it in his Sahih, which has the same level of acceptance among the experts as Sahih Muslim.
Source: Encylopedia of Islamic Doctrine