The works of Ādi Śaṅkarācārya

Sanatsujātīyam

p. 280

p. 280

कालेन पादं लभते तथायं तथैव पादं गुरुयोगतश्च ।

In plain words

Through time the student gains a quarter of knowledge, and likewise another quarter through connection with the teacher.

Close to the Sanskrit

By time this one obtains a quarter, and thus precisely a quarter through connection with the guru.