Then = Therefore: i.e. on account of the facts stated in verses: Joh_3:22-24.
question = questioning.
between some of = [on the part] of. Greek ek.App-104.
and = with. Greek. meta.App-104. the Jews. All the texts read "a Jew". Greek. Ioudaion, with Syriac. But it has been suggested that Iou was the primitive abbreviation for Iesou (= of Jesus), and being repeated (by inadvertence) led to the reading Iou[daion] (= a Jew). This would agree better with verses: Joh_3:22-24; with "Therefore" in Joh_3:26, and with the action of John's disciples, and John's answer. See the Structure H2 above.