Sahih al-Bukhari 756
Sahih al-Bukhari · Book 10: Call to Prayers (Adhaan) · Recitation of the Qur'an (Surat Al-Fatiha) is compulsory for the Imam and the followers, at the home and on journey, in all As-Salat (the prayers) whether the recitation is done silently or aloud.
Narrated 'Ubada bin As-Samit:
حَدَّثَنَا عَلِيُّ بْنُ عَبْدِ اللَّهِ ، قَالَ حَدَّثَنَا سُفْيَانُ ، قَالَ حَدَّثَنَا الزُّهْرِيُّ ، عَنْ مَحْمُودِ بْنِ الرَّبِيعِ ، عَنْ عُبَادَةَ بْنِ الصَّامِتِ ، أَنَّ رَسُولَ اللَّهِ صلى الله عليه وسلم قَالَ " لاَ صَلاَةَ لِمَنْ لَمْ يَقْرَأْ بِفَاتِحَةِ الْكِتَابِ " .
Allah's Messenger (ﷺ) said, "Whoever does not recite Al-Fatiha in his prayer, his prayer is invalid."