It wasnarrated that 'Aishah said:
"The Prophet (ﷺ) used to reciteQur'an sitting down, then when he wanted to bow he would stand upforas long as it takes a person to recite forty Verses." (PT)
English reference (PT): Vol. 1, Book 5, Hadith 1226 (PT)
Arabic reference (PT): Book 5, Hadith 1284 (PT)