Luke 9:48
And said unto them, Whosoever shall receive this child in my name receiveth me: and whosoever shall receive me receiveth him that sent me: for he that is least among you all, the same shall be great. And said unto them, Whosoever shall receive this child in my name receiveth me: and whosoever shall receive me receiveth him that sent me: for he that is least among you all, the same shall be great.
The verse belongs to the broader teaching in Luke 9:26-62 that must be studied to get its meaning, so that hearts are in full harmony with Christ and intelligent about His work and what He will do for those who follow on to know the Lord, whose going forth is prepared as the morning with continual increase of light. It was spoken while reflecting light upon the people when the time was nearly come to be taken from them, with the desire that they remember all that had been said because a time of trials and persecutions everywhere would come.
Whoever receives a child in His name receives Him. Whoever receives Him receives the Father who sent Him. The one who is least among all is the one who is great, for greatness in His kingdom is humility and taking the lowest place, not rank or rivalry.
The child placed among the disciples illustrates the humility to be learned, for followers must become humble like that child to enter the kingdom of heaven. Understanding this lesson helps a follower recognize personal weakness and Christ's power and so trust and obey the Master, as happened with Peter.
Receiving His messengers and workers is receiving Him, so those who care for God's workers should treat them with sympathy and generosity rather than indifference or selfishness, for He counts their welcome as welcome to Himself and such care honors Him.