During the prayer of the Eighteen Benedictions thou shouldst remove all the affairs of this world from thy heart; think of no other matter except of fixing thy mind on the prayer with perfect devotion. Prepare and purify thy heart and mind before God, blessed be He; thereby thy prayer will be pure, clean, untainted, full of devotion, and acceptable before the Holy One, blessed be His name, as it is written: ‘Thou wilt direct their heart, Thou wilt cause Thine ear to attend.’[197] Death and life are in the power of the tongue, and he that keeps his mouth and tongue, keeps his soul from troubles. Therefore in every matter think of thy words before thou givest utterance to them, all the days of thy life, so that thou mayest not sin; thereby thy thoughts, words, and deeds will be upright and good. My son, read this epistle once a week with thy friend, and walk continually after God, blessed be He, in order that thou mayest prosper in all thy ways and be worthy of the world to come which is stored up for the righteous. Whenever thou readest it, thou wilt get an answer from Heaven to all petitions which thou mayest ask from this time forth and for evermore. XXXI. SOLOMON B. ABRAHAM IBN ADRET [Celebrated authority on Halakah and zealous defender of traditional Judaism. He was born at Barcelona in 1235, and died in 1310. He was exceedingly active as Rabbi and author. His numerous responsa have been recognized as an important source for the internal history of the Jews in the thirteenth century.] Epistle Prohibiting Anyone Under Twenty-Five Years of Age to Study Philosophy[198]