King James Bible
"And he opened his mouth, and taught them, saying,"
This formal expression signals the beginning of authoritative teaching, echoing Old Testament prophetic language. The phrase emphasizes the solemnity and intentionality of what Jesus is about to say, marking the transition from narrative to direct discourse. Matthew identifies Jesus' primary activity as teaching his disciples, positioning him as the new Moses delivering divine instruction. This introduction frames the Sermon on the Mount as systematic instruction rather than casual conversation, establishing Jesus' role as the definitive teacher of God's kingdom.