四分律刪繁補闕行事鈔 1.439

1.439

一依止意者。新受戒者，創入佛法，萬事無知，動便違教；若不假師示導，進誘心神，法身慧命，將何所託？故律中制，未滿五歲，及滿五夏愚癡者，令依止有德；使咨承法訓，匠成己益。

First, the intent of taking dependence. Newly ordained ones have just entered the Buddha's Dharma and are ignorant of all matters, continually transgressing the teachings in their actions. If they do not rely on a master to guide them and lead their minds forward, on what can their Dharma-body and wisdom-life depend? Therefore, the vinaya institutes the rule that those with fewer than five rains [since ordination], as well as those who have completed five rains but remain foolish and ignorant, must take dependence upon the virtuous, causing them to consult and receive teachings on the Dharma, so as to be molded and achieve their own benefit.