Valmiki Ramayana Aranya Kanda Sarga 6 Shloka 14
Original Shlokaयत्करोति परं धर्म मुनिर्मूलफलाशनः। तत्र राज्ञश्चतुर्भाग प्रजा धर्मेण रक्षितः।।3.6.14।।
1 source checked for this shloka
मुनिः sage, यत् whatever, परम् supreme, धर्मम् merit, करोति earns, तत्र there, चतुर्भागः fourth portion, प्रजाः people, धर्मेण righteously, रक्षितः for him who protects.
One fourth of the supreme merit a sage earns by living on fruits and roots, accrues to the king through which the people are protected righteously.