ततः क्रमेण तपसा शास्त्रार्थनियमैः क्रमैः ।विवेक आजगामैनं नवर्तुरिव भूतलम्
In plain words
Then, by degrees, through tapas and through the ordered disciplines enjoined by the meaning of the śāstras, viveka came upon him, as a new season comes upon the earth.