John Calvin Commentary Luke 2:47

"and all that heard him were amazed at his understanding and his answers." — Luke 2:47 (ASV)

And all who heard him. Two things here claim our attention. All who heard him were astonished: for they considered it a miracle that a child should frame his questions with such correctness and propriety.

Again, they heard Christ, and thus acted the part more of scholars than of teachers.

He had not yet been called by the Father to declare himself a public teacher of the Church, and therefore contented himself with putting modest questions to the doctors.

Yet there is no room to doubt that, in this first attempt, he already began to critique their perverse way of teaching: for what Luke afterwards says about answers, I consider as denoting, according to the Hebrew idiom, any kind of discourse.