פירוש על ברכות 28:16

To read the Shema' before putting on the Tefillin. From the following discussion it will be seen that this was not Rab's regular practice, but he did so on one occasion.

Edd. add בקבר "in a grave," which is probably a gloss. M. reads בקיר "in a wall" i.e. of a cave or vault, where graves were often excavated. See J.E. III. p. 437, T.A. II. pp. 72 ff.

On the principle "One who is occupied with a religions duty is exempt from a religious duty." Cf. the discussion on fol. 11a, p. 68.