Sanhedrin

Our Rabbis taught: The year may not be intercalated before the New Year,  and if it be intercalated, the intercalation is invalid. In case of necessity,  however, a year may be intercalated immediately after the New Year; yet even so, only a [second] Adar is added.  But is this really so? Was not a message once sent to Raba:  'A couple [of scholars] have arrived from Rakkath  who had been captured by an eagle  whilst in possession of articles manufactured at Luz, such as purple,  yet through Divine mercy and their own merits they escaped safely. Further, the offspring of Nahshon  wished to establish a Nezib,  but yon Edomite  would not permit it.  The Members of the Assembly,  however, met and established a Nezib in the month in which Aaron the Priest died'?  Yes, the calculations were indeed made, but not published [until after the New Year]. How was it implied that the term Nezib [mentioned in the message] connoted 'month'? — Because is is written, Now Solomon had twelve Officers [Nezibim] over all Israel who provided victuals for the king and his household; each man his month in the year.  (But is it not written, And one officer [Nezib] that was in the land?  — Rab Judah and R. Nahman — one holds that one single officer was appointed over all [the other officers]: the other is of the opinion that this refers to the [special officer in charge of the provisions during] the intercalated month.) Our Rabbis taught: We may not, in the current year, intercalate the following year,  nor intercalate three years in succession. R. Simeon said: It once happened that R. Akiba, when kept in prison,  intercalated three years in succession. The Rabbis, however, retorted: 'Is that your proof? The court sat and intercalated each year at its proper time.' Our Rabbis taught: We may not intercalate a Sabbatical year  nor the year following a Sabbatical year. But which year was it usual to intercalate? — That preceding the Sabbatical year.  Those of the House of Rabban Gamaliel, however, used to intercalate the year following the Sabbatical year.  And this enters into the dispute of the following Tannaim. For it has been taught: Herbs may not be imported from outside the land [of Israel]. But our Rabbis permitted it. Wherein do they differ? — R. Jeremiah said: They differ as to whether we apprehend lest the earth attached to them [should also be imported]. Our Rabbis taught: We may not intercalate a year because of uncleanness.  R. Judah said: We may intercalate. R. Judah observed: It once happened that Hezekiah king of Judah declared a leap year because of uncleanness, and then prayed for mercy, for it is written, For the multitude of the people, even many of Ephraim and Manasseh, Issachar and Zebulun had not cleansed themselves,