Luke 2:33 New English Translation

³³So^[a] the child’s^[b] father^[c] and mother were amazed^[d] at what was said about him.

Luke 2:33 tn Here καί (kai) has been translated as “so” to indicate the consequential nature of the action.
Luke 2:33 tn Grk “his”; the referent (the child) has been specified in the translation for clarity.
Luke 2:33 tc Most mss ([A] Θ [Ψ] ƒ¹³ 33 M it) read “Joseph,” but in favor of the reading ὁ πατὴρ αὐτοῦ (ho patēr autou, “his father”) is both external (א B D L W 1 700 1241 sa) and internal evidence. Internally, the fact that Mary is not named at this point and that “Joseph” is an obviously motivated reading, intended to prevent confusion over the virgin conception of Christ, argues strongly for ὁ πατὴρ αὐτοῦ as the authentic reading here. See also the tc note on “parents” in 2:43.
Luke 2:33 tn The term refers to the amazement at what was happening as in other places in Luke 1-2 (1:63; 2:18). The participle is plural, while the finite verb used in the periphrastic construction is singular, perhaps to show a unity in the parents’ response (BDF §135.1.d: Luke 8:19).

New English Translation (NET)