Sunan Ibn Majah
1226
Sahih+3

It was narrated that ‘Aishah said:“The Prophet (ﷺ) used to recite Qur’an sitting down, then when he wanted to bow he would stand up for as long as it takes a person to recite forty Verses.”

SahihAl-Albani
SahihMuhammad Fouad Abd al-Baqi