Theophylact of Ohrid
Catena Aurea · Lukasevangelium 18
And they brought unto him also infants, that he would touch them: but when his disciples saw it, they rebuked them. But Jesus called them unto him, and said, Suffer little children to come unto me, and forbid them not: for of such is the kingdom of God. Verily I say unto you, Whosoever shall not receive the kingdom of God as a little child shall in no wise enter therein.
After what He had said, our Lord teaches us a lesson of humility by His own example; He does not turn away the little children who are brought to Him, but graciously receives them.