Megillah, Chapter Four, Mishnah Five
This mishnah and the mishnayot following it deal with who is qualified to receive certain honors in the synagogue.
I have explained this mishnah according to Albecks explanation. Others explain it somewhat differently.
1) The one who concludes with the haftarah also leads the responsive reading of the Shema and he passes before the ark and he lifts up his hands.
2) If he is a child, his father or his teacher passes before the ark in his place.
Section one: The person honored by reading the haftarah is worthy of also being the leader of the other crucial elements of the service. He can lead the responsive reading of the Shema (explained in yesterdays mishnah), he can pass before the ark (meaning recite the Amidah and thereby aid others in fulfilling their obligation) and if he is a priest, he can lift up his hands to bless the people with the priestly blessing. In the proceeding mishnayot we will see that not everyone is worthy of these honors.
Section two: A child is allowed to read the haftarah, but he may not pass before the ark. The person who recites the amidah (passes before the ark) helps others to fulfill their obligation to recite the amidah. In order to help others fulfill their obligation, the person himself must also be obligated. A child who is not obligated cannot fulfill the congregations obligation. Therefore, if a child read the haftarah either his father or teacher takes his place in passing before the ark.