According to Jainism, after attaining Kevalgyan (omniscience), the Tirthankaras walk on a special type of divine platform called Samavasarana. Within the Samavasarana, it is believed that the ground is covered with precious gems and flowers so that not even the smallest living beings are harmed by their walking, as Tirthankaras possess perfect non-violence (ahimsa).

Specifically, Jain scriptures mention that after attaining Kevalgyan, the Tirthankara does not walk on ordinary ground but rather on a Pandukashila (a slab or platform made of yellowish stones), or sometimes described as walking on a carpet of flowers and gems. This ensures that no living beings are harmed by their steps, upholding the principle of ahimsa to the highest degree.

In summary: After attaining Kevalgyan, a Tirthankara walks on the Pandukashila or the special, divinely-prepared ground in the Samavasarana, not on ordinary earth.