See on Luk 15:15. Compare Aeschylus: “The family has been glued (κεκόλληται) to misfortune” (“Agamemnon,” 1543). The verb is used Gen 2:24, Sept., of the relation of husband and wife: shall cleave. In Deu 10:20; Deu 11:22; Jer 13:11, of man's cleaving to God.
To a harlot (τῇ πόρνῃ)
Lit., the harlot. The article is significant: his harlot, or that one with whom he is sinning at the time.
Shall be one flesh (ἔσονται εἰς σάρκα μίαν)
Lit., shall be unto one flesh: i.e., from being two, shall pass into one. Hence Rev., rightly, shall become. Compare Eph 2:15.