Whosoever, &c. This verse is not "loosely connected", or "out of any connexion" with what precedes, as alleged. The Structure above shows its true place, in C1, how the Pharisees made void the law (as to divorce); and C2, how they made void the prophets (verses: Luke 16:16; Luke 16:17) and the rest of Scripture as to the dead (verses: 19-23).
putteth away, &c. The Rabbis made void the law and the prophets by their traditions, evading Deuteronomy 22:22, and their "scandalous licence" regarding Deuteronomy 24:1. See John Lightfoot, Works (1658), J. R. Pitman's edn. (1823), vol. xi, pp. 116-21 for the many frivolous grounds for divorce.