Reference for Pesachim 135:3
מיתיבי מצורע חמור מזב וזב חמור מטמא מת יצא בעל קרי שטמא מת חמור ממנו
A tanna recited before R. Isaac b. Abdimi: Then he shall go abroad out of the camp: this means the camp of the Shechinah; he shall not come within the camp: this means the Levitical camp. From this [we learn] that a ba'al keri must go without the two camps. Said he to him, You have not yet brought him in that you should [already] expel him! Another version: you have not yet expelled him, and [already] you [discuss whether] he should enter! Rather say: 'abroad out of the camp' - this is the Levitical camp; 'he shall not come within the camp'- that is the camp of the Shechinah. To this Rabina demurred: Assume that both refer to the camp of the Shechinah, [it being repeated] so that he should violate an affirmative command and a negative command on its account? If so, let Scripture say, 'Then he shall go abroad out of the camp' and 'he shall not enter": what is the purpose of 'within the camp'? Infer from it that it is to prescribe another camp for him. <br>