These little ones were considered part of God’s covenant people. The commentator Matthew Henry said of this: “Not the men only, but their wives and children, must come into this covenant; though they were not numbered and mustered, yet they must be joined to the Lord. Observe, even little ones are capable of being taken into covenant with God and are to be admitted with their parents. Little children, so little as to be carried in arms, must be brought to Christ, and shall be blessed by Him.”
In Joshua 8:35, we see children (toddlers, according to the Hebrew), present for the reading of God’s Word: “There was not a word of all that Moses had commanded which Joshua did not read before all the assembly of Israel, with the women, the little ones, and the strangers who were living among them” (NKJV).
The Bible tells us that the commandments of God are not intended merely for adults, but also for the little ones of God. This was no short 15 or 20-minute service. Joshua read all that Moses commanded. This does not necessarily mean that the entirety of the first five books of the Bible was read out at one time, but that the length of the service was not accommodated to children’s attention span. The implication is the reverse: children, toddlers, were in the process of accommodating (that is, they were trained by their parents) to the Word of God.
The Lord Jesus had much to say about these covenant children: see Matt.19:13-15; Mark 10:14ff; Luke 18:17; Luke 9:46-48; Mark 9:33ff, among others. The words used to describe these children in the Greek span several stages of development: from embryo in the womb to infant, from pre-weaned children to those just weaned, from those who are without the power of speech to those who could cry “Hosanna!” The most powerful of these passages is that of Matthew 19:13-15: “Then the little children were brought to Him that He might put [His] hands on them and pray, but the disciples rebuked them. But Jesus said, “Let the little children come to Me, and do not forbid them; for of such is the kingdom of heaven.” And He laid [His] hands on them and departed from there” (NKJV).
Christ was indignant (see the parallel passage in Mark) with his disciples, who sought to restrain the access of these children to Him. None are too young or too little to bring to Christ.
These children are sinners (as are we all) who need to hear the Word of Christ, to grow up in the nurture and admonition of the Lord (Eph.6). To deny them access to the Word of God is to cut them off from the means that God has ordained for the communication of His Gospel (Romans 10).