On the prohibition against praying towards graves

Riyad as-Salihin (The Meadows of the Righteous)

by Imam Nawawi

342. Chapter: On the prohibition against praying towards graves

1757. Abu Marthad Kannaz ibn al-Husayn said, "I heard the Messenger of Allah, may Allah bless him and grant him peace, say, 'Do not pray towards graves nor sit on them." [Muslim]