SB 8.7.10
surasurendrair bhuja-virya-vepitam
paribhramantam girim anga prsthatah
bibhrat tad-avartanam adi-kacchapo
mene ’nga-kanduyanam aprameyah
Translation by His Divine Grace A. C. Bhaktivedanta Swami Srila Prabhupada:
O King, when the demigods and demons, by the strength of their arms, rotated Mandara Mountain on the back of the extraordinary tortoise, the tortoise accepted the rolling of the mountain as a means of scratching His body, and thus He felt a pleasing sensation.
Purport by His Divine Grace A. C. Bhaktivedanta Swami Srila Prabhupada:
The Supreme Personality of Godhead is always the unlimited. Although the Supreme Personality of Godhead, in His body as a tortoise, held on His back the largest of mountains, Mandara-parvata, He did not feel any inconvenience. On the contrary, He apparently felt some itching, and thus the rotation of the mountain was certainly very pleasing.