As-salamu alaikum wa Rahmatullahi wa Barakatoh,
Holy Prophet Muhammad al Mustafā (salla llāhu ʿalayhi wa-alehe wa-sallam) said:
"Whoever fasts on the first three days of Sha’ban, and wakes up at nights and says two units of prayers and in each unit he recites the Opening Chapter once and ‘Surah Tawheed’ eleven times, Allāh the Sublime would fend off the evils of the people of the heavens and the earth, the evils of Satan and his troops, and the evils of all oppressive kings from him. I swear by Him who rightfully appointed me to the Prophethood that Allāh would forgive seventy-thousand major sins that are between him and God the Honorable the Exalted, and would fend off the torture of the grave, the departure of the soul from the body, and its hardships."
[Reference: Supplications and Deeds for the Whole Year, pg 392]