Numbers 13:11 - Coke's Commentary on the Holy Bible

Of the tribe of Joseph, &c.— That is to say, of that part of the tribe of Joseph whereof Manasseh was the chief. Mention is made of the tribe of Ephraim, the other branch of the tribe of Joseph, in the 8th verse. The name of Joseph was common to each; but Poole is of opinion, that it is given in this particular manner to Manasseh, to shew in the stronger point of view the crime of the chief of this tribe, who conducted himself so unworthily of his great forefather Joseph. Ainsworth, however, thinks that Manasseh is only mentioned thus, as being the eldest.