Hadith Qudsi are the sayings of the Prophet Muhammad (Peace and Blessings of Allah be upon him) as revealed to him by the Almighty Allah. Hadith Qudsi (or Sacred Hadith) are so named because, unlike the majority of Hadith which are Prophetic Hadith, their authority (Sanad) is traced back not to the Prophet but to the Almighty.
Among the many definitions given by the early scholars to Sacred Hadith is that of as-Sayyid ash-Sharif al-Jurjani (died in 816 A.H.) in his lexicon At-Tarifat where he says: “A Sacred Hadith is, as to the meaning, from Allah the Almighty; as to the wording, it is from the messenger of Allah (peace be upon him). It is that which Allah the Almighty has communicated to His Prophet through revelation or in dream, and he, peace be upon him, has communicated it in his own words. Thus Qur’an is superior to it because, besides being revealed, it is His wording.”
On the authority of Anas (may Allah be pleased with him), who said: I heard the Messenger of Allah (peace be upon him) say: Allah the Almighty said:
O son of Adam, so long as you call upon Me and ask of Me, I shall forgive you for what you have done, and I shall not mind. O son of Adam, were your sins to reach the clouds of the sky and were you then to ask forgiveness of Me, I would forgive you. O son of Adam, were you to come to Me with sins nearly as great as the earth and were you then to face Me, ascribing no partner to Me, I would bring you forgiveness nearly as great at it.
It was related by at-Tirmidhi (also by Ahmad ibn Hanbal). Its chain of authorities is sound.