Surya Siddhanta
एवम् बुधो द्वादशभिश् चतुर्दशभिर् अम्शकैः। वक्री शीघ्रगतिश् चार्कात् करोत्य् अस्त्मयोदयौ॥
Likewise for Mercury, the setting and rising occur at a distance of 12 and 14 degrees from the sun, accordingly as it is retrograding or rapidly advancing.
english translation
evam budho dvAdazabhiz caturdazabhir amzakaiH। vakrI zIghragatiz cArkAt karoty astmayodayau॥
hk transliteration by Sanscript