Berachos 3b - Part 2

Tanu Rabbanan:

The Baraissa brings an argument between Rebbi and R' Nosson. Rebbi holds that there are 4 watches in the night. R' Nosson holds there are three.

The Gemara now analyzes the two positions:

R' Nosson's position: R' Nosson bases his opinion that there are 3 mishmaros on a pasuk in Shoftim 7. The pasuk talks about Gideon coming with his men "at the beginning of the middle mishmar. If there is a "middle" mishmar, there must only be three mishmaros, and not four. Rebbi would respond that the pasuk only means one of the two middle watches. R' Nosson responds back that it doesn't say that.

Rebbi's position: Rebbi bases his opinion that there are 4 mishmaros on a pasuk in Tehillim 119. This source is brought by R' Zreika in the name of R' Ami in the name of R' Yehoshua ben Levi. The pasuk says that King David arises at chatzos (midnight) to thank Hashem. The pasuk also says that two ashmaros remain from midnight until daytime. This clearly implies that there are 4 mishmaros.

The Gemara offers two possible responses of R' Nosson:

Response #1: R' Nosson follows R' Yehoshua's opinion in a Mishna in Berachos 9b. There R' Yehoshua says that the zman of the morning shma ends 3 hours into the day, because kings get up then. King David, in that case, would've gotten up 2 hours late (arising at the beginning of the 3rd hour). Thus, if he wakes at midnight he is getting up 8 hours early. Since there are 3 mishmaros (acc. to R' Nosson) each mishmar is 4 hours. So, essentially, 8 hours is two mishmaros, which is why King David says that he arises two mishmaros early.

Response #2: R' Ashi answers more simply that really King David arose 1.5 mishmaros early. We can refer to 1.5 mishmaros as 2 mishmaros.