Matthew Poole and continuators on Numbers 11:26

26 But there remained two of the men in the camp , the name of the one was Eldad, and the name of the other, Medad: and the spirit rested upon them (and they were of them that were written , but went not out unto the tabernacle) and they prophesied in the camp.

Not going to the Tabernacle, as the rest did, either modestly declining that high employment from an humble sence of their own insufficiency, as Saul did, 1 Sam. 10. 22. or not having sufficient or seasonable notice to repair thither: or, being detained in the camp and in their dwellings whether by uncleanness, or sickness, or some urgent occasion, not without Gods special providence, that so the Miracle might be more evident, and their call and authority more unquestionable to all the people.

To wit in a book or paper by Moses, who by Gods direction nominated the fittest and worthiest persons.