There is a Hadith in Jame’ Tirmidhi, Musnad Ahmed, Mustadrak ‘Alas Sahihain, Umdatul Qari, Tafseer Ibn Kathir, Subul Ul Huda War Rashad:
Translation of Hadith: Hadhrat Akrama (May Allah be well pleased with him) says: Hadhrat Abdullah in Abbas (May Allah be well pleased with them) says: Hadhrat Muhammad Mustafa (Sallallahu alaihi wa sallam) saw His Lord. I said: Did not Allah Ta’ala say, “No sight can grasp His vision”:
He said: I am surprised you! This is when Allah Ta’ala expresses His that Noor, which is boundless. Hadhrat Muhammad (Sallallahu alaihi wa sallam) did see His Lord 2 times. (Jame’ Tirmidhi, ABwab Ut Tafseer, Hadith No. 3590; Umdatul Qari Sharh Sahih Bukhari, Kitab Ut Tafseeril Quran, Surah Najm-5, Vol. 7, Pg. No. 442; Subul Ul Huda War Rashad, Vol. 3, Pg. No. 61; Mustadrak ‘Alas Sahihain, Kitab Ut Tafseer, Surah An’aam, Hadith No. 3191; Musnad Imam Ahmed, Mo’jam Kabeer, Tafseer Ibn Abi Hatim, Surah An’aam, Hadith No. 7767)
Translation of Hadith: Hadhrat Abdullah Bin Abbas (May Allah be well pleased with them) said: The Holy Prophet (Sallallahu alaihi wa sallam) saw His Lord. (Jame’ Tirmidhi, Vol. 2, Pg. No. 164, Hadith No. 3202).
Musnad Imam Ahmed has the following words:
Translation of Hadith: Hadhrat Abdullah Bin Abbas (May Allah be well pleased with them) says: The Holy Prophet (Sallallahu alaihi wa sallam) says: I have seen my Lord. This Hadith is mentioned in Musnad Imam Ahmed twice. (Musnad Imam Ahmed, Hadith No. 2449/2502)
Hadhrat Ka’ab (May Allah be well pleased with him) says: Allah Ta’ala has divided His vision (i.e. seeing Him) and His Speech between Hadhrat Muhammad Mustafa (Sallallahu alaihi wa sallam) and Hadhrat Moosa (peace be upon him). Hadhrat Moosa (peace be upon him) talked with Allah Ta’ala and twice, Hadhrat Muhammad (Sallallahu alaihi wa sallam) saw His Lord. (Jame’ Tirmidhi, Hadith No. 3678)
It is mentioned in Imam Tabarani’s M’ojam Ausat:
Translation of Hadith: Indeed, Hadhrat Muhammad (Sallallahu alaihi wa sallam) saw His Lord twice. (M’ojam Ausat, Hadith No. 5922; Mawahib Ladunniya, Vol. 8, Pg. No. 248)