and we have not reached [information] that the Prophet (may Allah bless him and grant him peace) disapproved of it, [nor did any of his companions] (39); and because that for which the prayer is valid when it is in large amount in a state of excuse, a distinction is made between its small amount and its large amount in the state of no excuse, like walking. And because guarding against a small amount is difficult, so it is excused, like a small amount of blood.

Once this is established, the limit of a 'large amount' is that which is considered repulsive to the eye, and there is no difference in that between the private parts and other areas. A 'small amount' is that which is not considered repulsive, and the reference for that is custom, [except that for the severely private areas, that which would not be considered repulsive for others is considered repulsive, so this is taken into account regarding what prevents the prayer.] (40) Abu Hanifah said: If an amount equivalent to a dirham is exposed from the severely private areas, or [less than a quarter] (41) of the less private areas, the prayer is not invalidated (42). If it is more, it is invalidated. Our argument is that this is [an estimation for which the Law has provided no [evidence]] (43), [so it is not permissible to adopt it. Furthermore, that for which the Law has not provided an estimation is referred] (44) to common usage (al-'urf), like the large amount of movement in prayer, separation, and guarding (45), and estimating based on arbitrary opinion without evidence is not permissible.

Section: If his 'awrah is exposed unintentionally, and he covers it immediately without a lapse of time, it does not invalidate [the prayer]; because it is a small [amount of time] (46), similar to a small amount in quantity. [Abu al-Hasan] (47) al-Tamimi said, [in his book] (48): If his 'awrah appeared for a time and was covered for a time, he does not have to repeat it, based on the hadith of Amr ibn Salamah. He did not stipulate a small amount, nor must there be a stipulation of it; because the large amount [makes the exposure of the 'awrah repulsive] (49), and it is possible to guard against it, so it is not excused, just like the large amount in quantity.