Kitab-i-Iqan — Paragraph 222

Muhammad, Himself, as the end of His mission drew nigh, spoke these words: “Verily, I leave amongst you My twin weighty testimonies: The Book of God and My Family.” Although many traditions had been revealed by that Source of Prophethood and Mine of divine Guidance, yet He mentioned only that Book, thereby appointing it as the mightiest instrument and surest testimony for the seekers; a guide for the people until the Day of Resurrection.