“Teacher, Moses wrote for us, ‘If someone’s brother dies and leaves a wife behind, but leaves no child, his brother should marry his wife and provide offspring for his brother’ (Deut. 25:5).
The Sadducees refer to that ordinance of the Law of Moses which was given to preserve the family inheritance and a brother’s name (Deuteronomy 25:5–6). That ordinance concerned the conditions of the present life, the continuation of a mortal line, and the social order of Israel. Yet they try to apply that temporary ordinance to the eternal life of the resurrection, as though the same earthly relationships and needs will continue there. Their error is here: they imagine the eternal state within the limits of the present fallen world.