John Lightfoot on Matthew 21:15

[The children crying in the temple, and saying, Hosanna.] Children, from their first infancy, were taught to manage the bundles, to shake them, and in shaking, to sing Hosanna. A child, so soon as he knows how to wave the bundle, is bound to carry a bundle Where the Gemara saith thus; "The Rabbins teach, that so soon as a little child can be taught to manage a bundle, he is bound to carry one: so soon as he knows how to veil himself, he must put on the borders: as soon as he knows how to keep his father's phylacteries, he must put on his own: as soon as he can speak, let his father teach him the law, and to say the phylacteries," &c.