A custom (συνηθεια). Old word for intimacy, intercourse, from συνηθης (συν, ηθος), in N.T. only here, 1 Corinthians 8:7; 1 Corinthians 11:16. This custom, alluded to in Mark 15:6; Matthew 27:15, is termed necessity (αναγκη) in Luke 23:17 (late MSS., not in older MSS.). All the Gospels use the verb απολυω (release, set free). Then ινα απολυσω is a subject clause (ινα and first aorist active subjunctive) in apposition with συνηθεια.

Will ye therefore that I release? (βουλεσθε ουν απολυσω;). Without the usual ινα before απολυσω, asyndeton, as in Mark 10:36, to be explained either as parataxis or two questions (Robertson, Grammar, p. 430) or as mere omission of ινα (ibid., p. 994). There is contempt and irony in Pilate's use of the phrase "the king of the Jews."