EXOD116 [This verse] was understood to mean: you shall distinguish yourselves by your devotion to God and engage in the study of Torah rather than other matters. If a man cannot give the entire day to study, let him study a couple of halachahs in the morning and in the evening. His study in the morning does not exempt him from studying in the evening, any more than his morning prayer absolves him from the obligation to pray in the evening. [Mekiltah, Bahodesh 2; Al Nakawa, Menorat Hamaaor III, 374-5]. The opinion is voiced that if a man study only one chapter of the Torah in the morning and one in the evening he has fulfilled the command of Joshua 1:8, "This book of the Law shown not depart out of thy mouth, but thou shalt meditate therein day and night." The view was further expressed that the command is fulfilled even if one recites no more than the Shema in the morning and evening.