"The priesthood was apportioned to Levi, the kingdom and the Messianic promise to Judah, and the double portion of the inheritance to Joseph. The tribe of Reuben never rose to any eminence in Israel; it was not so numerous as Judah, Joseph, or Dan, and was among the first that were carried into captivity. PP 235.6"
The passage mentions Reuben's tribe not being as numerous, which could relate to census records like Numbers 1:21.
Numbers 1:51"And when the tabernacle setteth forward, the Levites shall take it down: and when the tabernacle is to be pitched, the Levites shall set it up: and the stranger that cometh nigh shall be put to death."
The Lord designated a special family of the tribe of Levi to bear the ark; and others of the Levites were specially appointed of God to bear the tabernacle and all its furniture, and to perform the work of setting up and taking down the tabernacle. And if any man from curiosity or from lack of order got out of his place and touched any part of the sanctuary or furniture, or even came near any of the workmen, he was to be put to death. God did not leave His holy tabernacle to be borne, erected, and taken down, indiscriminately, by any tribe who might choose the office; but persons were chosen who could appreciate the sacredness of the work in which they were engaged. These men appointed of God were directed to impress upon the people the special sacredness of the ark and all that appertained thereunto, lest they should look upon these things without realizing their holiness and should be cut off from Israel. All things pertaining to the most holy place were to be looked upon with revere…
The EGW passage directly alludes to Numbers 1:51, which states that the Levites are responsible for taking down and setting up the tabernacle, and that unauthorized individuals who approach it will be put to death. The EGW passage expands on this concept, emphasizing the sacredness of the work and the importance of following God's instructions.