A man reported,

A man prayed while the Prophet ﷺ was watching him. When he finished his prayer, the Prophet ﷺ said, "Go back and pray, for you have not prayed."The man stood up and prayed again, but when he finished, the Prophet ﷺ said three times, "Go back and pray."The man swore to him, "How? I tried my best."So the Prophet ﷺ said to him, "Begin by saying the takbir, then praise Allah, then recite the Mother of the Quran, then bow..." and he mentioned the rest of the hadith.

Azami 1971

Sahih

عن رجل من أصحاب النبي ﷺ قال

صلى رجل، والنبي ﷺ ينظر إليه. فلما قضى صلاته، قال: ارجع فصل فإنك لم تصل ثلاثا. فقام الرجل، فلما قضى صلاته. قال النبي ﷺ: ارجع فصل ثلاثا. قال: فحلف له كيف؟ اجتهدت كذا فقال له: ابدأ، فكبر وتحمد الله وتقرأ بأم القرآن، ثم تركع… فذكر الحديث.

الأعظمي 1971صحيح
Contents
Reference
Commentary
Ayat
Collection
Jami al-Kamil
Book
Prayer
Chapter
Description of prayer, the takbir, standing, and recitation
Section
Obligation of reciting Surah Fatihah
Numbering
Jami al-Kamil 1971 (2nd edition)
Azami 1971