The works of Ādi Śaṅkarācārya

Sanatsujātīyam

p. 280

p. 280

उत्साहयोगेन च पादमृच्छेच्छास्त्रेण पादं च ततोऽभियाति ॥

In plain words

One quarter he gains by sheer drive put to work, and one quarter from the śāstra itself — and from there he goes the rest of the way.

Close to the Sanskrit

And by the application of zeal he would reach a quarter, and a quarter by the śāstra; from that he goes forward.