Valmiki Ramayana Bala Kanda Sarga 66 Shloka 13

अथ thereafter, मे my, क्षेत्रम् the sacrificial ground, कृषत: while I was ploughing, लाङ्गूलात् by the blade of plough, उत्थिता lifted, नाम्ना by name, सीतेति Sita, विश्रुता wellknown, क्षेत्रम् that sacrificial ground, शोधयता purifying, मया by me, लब्धा obtained.

Thereupon while I was ploughing and cleaing the (sacrificial) ground, Sita, a wellknown name, was lifted up by the blade of the plough. Thus she was obtained by me.