四分律行事鈔資持記 1.869

1.869

二中。言心退者，鈍根未堪，故開後誦，不過五夏；《四分》先誦經論，及病，亦開。

In the second: the words 'the mind regresses' mean that those of dull faculties are not yet capable, hence an exception is granted to recite it later, not to exceed five summers; the Dharmaguptaka also grants an exception for reciting sūtras and treatises beforehand, as well as for illness.