Dictionary of Biblical Words:
An expression taken from Matt. 23:18, where the Lord’s presence is promised to two or three gathered to His name. The small number doubtless refers to times when no more than this can be found thus to assemble together; to such this promise is very precious, giving as it does to those thus assembled all the power of the assembly (1 Con, 5.). The name spoken of doubtless refers to Matt. 16, when Jesus expressly takes the name of Christ no longer as the Jewish Messiah, but as the foundation of the church He was about to build, and which is referred to in chap. 18.
Concise Bible Dictionary:
See NUMBERS AS SYMBOLS.