Praise be to Allah.
This hadeeth (report) is not part of the Prophet’s (peace and blessings of Allah be upon him) Sunnah (teachings), and it is not something that is known to the scholars and muhaddithoon (scholars of hadeeth) in their books and Musnads. It is not narrated except in a few books whose authors filled them with fabricated reports, false reports, stories and myths, such as Nuzhat al-Majalis wa Muntakhab al-Nafa’is, by the historian and man of letters ‘Abd al-Rahman ibn ‘Abd al-Salam al-Safoori (d. 894 AH) – pp. 182-183, Chapter on the virtue of Ramadan and encouragement to do good deeds therein. It also appears in the tafseer Rooh al-Bayan (8/112) by Isma’eel Haqqi al-Hanafi al-Khalooti (d. 1127 AH). They mentioned a hadeeth similar to the one referred to by the questioner, in which it says: “Moosa (peace be upon him) said: ‘O Lord, You have honoured me by speaking to me directly. Will You give anyone else something like this?’ And Allah revealed: ‘O Moosa, I have slaves whom I will bring forth at the end of time, and I will honour them with the month of Ramadan, and I will be closer to one of them than to you, because you have spoken to Me when there are 70,000 veils between Me and you, but when the ummah of Muhammad (peace and blessings of Allah be upon him) fasts until their lips turn white and their faces turn yellow, I will lift the veil between Me and them at the time they break their fast. O Moosa, glad tidings to the one whose liver thirsts and whose stomach hungers in Ramadan.”
Moreover, in the matn (text) of this hadeeth there is something which indicates that it is munkar (i.e., unsound), which is the words “I will be closer to one of them than you” – referring to Moosa (peace be upon him). It is well known in Muslim beliefs that the Messengers and Prophets are better than all other humans, and Moosa (peace be upon him) is one of the Messengers of strong will, so how can Allah be closer to His slaves than to His Prophet Moosa (peace be upon him), of whom He said (interpretation of the meaning): “And We called him from the right side of the Mount, and made him draw near to Us for a talk with him” [Maryam 19:52]? And Ibn ‘Abbas (may Allah be pleased with him) said: He drew so close that he heard the scratching of the Pen – i.e., writing the Tawrat (Torah). See: Tafseer al-Quran il-‘Azeem by al-Hafiz Ibn Katheer (5/237).
To sum up: The hadeeth mentioned is not in any of the reliable books, so it is not permissible to attribute it to the Messenger of Allah (peace and blessings of Allah be upon him) or to believe what it says.
And Allah knows best.