ācāryāt pādam ādatte pādaṁ
ācāryāt pādam ādatte pādaṁ śiṣyaḥ svamedhayā |
pādaṁ sabrahmacāribhyaḥ pādam kāla-krameṇa ca ||
(Āpastamba-dharma-sūtra)
“A student acquires one-fourth from the ācārya, one-fourth by his own intellect, one-fourth from fellow students, and one-fourth in the course of time.”