Shabbat

Why was it said that one must not put away [food] in a substance which adds heat, even by day? For fear lest he put it away in hot ashes containing a burning coal. Said Abaye to him, Then let him put it away! — [That is forbidden] for fear lest he rake the coals. Our Rabbis taught: As to twilight [period] it is doubtful whether it is partly day and partly night, or the whole of it [belongs to the] day, or the whole of it night: [therefore] it is cast upon the stringencies of both days.  And what is twilight? From sunset as long as the face of the east has a reddish glow: when the lower [horizon] is pale  but not the upper, it is twilight; [but] when the upper [horizon] is pale and the same as the lower, it is night: this is the opinion of R. Judah. R. Nehemiah said: For as long as it takes a man to walk half a mil  from sunset. R. Jose said: Twilight is as the twilight of an eye, one entering and the other departing,  and it is impossible to determine it. The Master said: 'One applies to it the stringencies of both days.' In respect of what [point of] law? — Said R. Huna son of R. Joshua, In respect of uncleanness. Even as we learnt: if he saw [discharges] on two days at twilight, he is doubtful in respect of uncleanness and sacrifice: if he sees [a discharge] one day at twilight, he is doubtful in respect of uncleanness. This is self-contradictory. You say, 'What is twilight? From sunset as long as the face of the east has a reddish glow.' Hence, if the lower horizon is pale but not the upper, it is night.  Then it is taught, 'When the lower [horizon] is pale but not the upper, it is twilight'? — Rabbah answered in the name of Rab Judah in Samuel's name: Combine [them] and learn: What is twilight? From sunset as long as the face of the east has a reddish glow, And if the lower [horizon] is pale but not the upper, that too is twilight. But when the upper horizon is pale and the same as the lower, it is night. While R. Joseph answered in the name of Rab Judah in Samuel's name, This is what he teaches: From sunset as long as the face of the east has a reddish glow, it is day; if the lower [horizon] is pale but not the upper, it is twilight; when the upper is pale and the same as the lower, it is night. Now, they follow their views. For it was stated: How long is the period of twilight? — Rabbah said in the name of Rab Judah in Samuel's name. Three parts of a mil.  What is meant by, 'three parts of a mil'? Shall we say, three half mils? Then let him say, 'A mil and a half'? While if it is three thirds of a mil, let him say, 'One mil'? Hence it must mean three quarters of a mil. While R. Joseph said in the name of Rab Judah in Rab's name: Two parts of a mil. What is 'two parts of a mil'? Shall we say, two halves: let him say, 'One mil'? while if it means two quarters of a mil; let him say, 'half a mil'. Hence