Brihat Parashara Hora Shastra
वर्गोत्तमगते लग्ने दशा चिन्त्या शताब्दिका । पौष्ण्भाज्जन्मपर्यन्तं गणयेत् सप्तभिर्भजेत् ॥ ३२॥
This happens, when Lagn in the Rāśi Kundali and the Navāńś Lagn are in the same Rāśi. Count from Revati to the Janm Nakshatr and divide this number by seven.
english translation
vargottamagate lagne dazA cintyA zatAbdikA । pauSNbhAjjanmaparyantaM gaNayet saptabhirbhajet ॥ 32॥
hk transliteration by Sanscript