Ruku‘ (Kneeling) and Readings therein and When Standing up Straight Thereafter

6. Ahmad ibn Idris has narrated from Ahmad ibn Muhammad from al-Husayn ibn Sa‘id from al-Qasim ibn Muhammad from a man from abu Basir from who has said the following: “Abu ’Abd Allah عليه السلام, has said, ‘When you stand up straight after Ruku‘ (bowing down on one’s knees), make your back (bones) stand straight (vertically), otherwise, one’s Salah (prayer) is not considered Salah (prayer).”’