“All of the mundane and supramundane good qualities of the Mahayana and Hinayana are the result of serenity and insight…. An undistracted mind is mental one-pointedness, the serenity aspect, while accurate reflection on facts and meanings refers to discerning wisdom, the insight aspect. Thus, you must achieve all good qualities of the two vehicles through both (1) sustained analysis with discerning wisdom and (2) one-pointed focus on the object of meditation. You do not achieve them through one-sided practice of either analytical meditation or stabilizing meditation.”
From The Great Treatise on the Stages of the Path to Enlightenment by Je Tsong Khapa
As translated in: The Great Treatise on the Stages of the Path to Enlightenment: The Lam Rim Chen Mo by Tsong Khapa. Translated by the Lamrim Chenmo Translation Committee. Snow Lion/Shambhala Publications.