Samuel Ministers in the Tabernacle (Mishkan): While many think he was a youngster, he had to be at least thirty years old.

1 Samuel 3.1. And the young man Samuel ministered to the LORD* before Eli. And the word of the LORD* was rare in those days. There was no frequent vision. 2. And it was at that time when Eli was lying down in his place and his eyes began to grow dim, he could not see. 3. And the lamp of God had not yet gone out and Samuel was lying down in the Temple of the LORD*, where the Ark of God was. 4. The LORD* called Samuel and he answered, Here I am. 5. And he ran to Eli and said, Here I am, for you called me.