[Praying One Thousand Rakʿahs in a Single Night]

Answer (and Allah grants success): This has been reported through solitary (āḥād) chains, and there is no obligation upon us that hinges on whether it is sound or not. There is no impediment to it: a long winter night could accommodate that amount if one enters with the opening takbīr and does not give salām until the end, abbreviating the recitation and the glorifications. On that basis, each minute would hold a rakʿah or part of one—especially with Allah’s blessing upon some of His righteous friends.
Still, the report may contain error, or it may be hyperbolic; the Arabs, when intending to exaggerate a great number, would express that multitude with “a thousand,” intending mere abundance rather than a precise count.
Yes, what has been narrated about Zayn al-ʿĀbidīn (peace be upon him) in al-Majmūʿ is that he might pray a thousand rakʿahs over the course of a day and a night.
This could be because supererogatory prayers are lightened: they are valid from a sitting position, by gesture (imāʾ) for bowing and prostration, and with shortened glorifications and recitation.
Source : Min Thimār al-ʿIlm wa al-Ḥikmah vol.1