Mark 12:28
One of the teachers of the law came and heard them debating. Noticing that Jesus had given them a good answer, he asked him, of all the commandments, which is the most important? — the scribe's question is asked not as a trap (unlike the Pharisees, Herodians, and Sadducees) but apparently as genuine inquiry stimulated by the quality of Jesus' previous answers. The greatest commandment question was a standard topic of rabbinic discussion — the attempt to find the principle that encompasses all the others.