It is narrated from Sayyiduna Abdullah bin Mas'ud (may Allah be pleased with him) that he said: When we learned ten verses of the Qur'an from the Prophet (peace and blessings be upon him), we would not learn the next ten verses until we had come to know the knowledge and practice contained in those (first ten verses). Sharik was asked: "Is practice meant by this?" He said: "Yes." This hadith has a sahih (authentic) chain of narration, but the two Shaykhs (Bukhari and Muslim) did not record it.