Arthashastra
षष्टि वेतनस्य आढकं कृत्वा हिरण्य अनुरूपं भक्तं कुर्यात् ॥
Substituting one ádhaka for the salar of 60 panas payment in gold may be commuted for that in kind.
english translation
SaSTi vetanasya ADhakaM kRtvA hiraNya anurUpaM bhaktaM kuryAt ॥
hk transliteration by Sanscript