The book illustrates this category with the Companions’ position concerning fighting those who withheld zakat during Abu Bakr’s rule.
«كإجماعهم على قتال مانعي الزكاة في عهد أبي بكر رضي الله عنه»
Such as their consensus about fighting those who withheld zakat in the time of Abu Bakr.
The usuli point is how the author classifies the historical example: an expressed position by some and silence or lack of objection by others. The brief example should not be taken as a full reconstruction of every historical circumstance.