Śaṅkara became celebrated by the name “the pillow of Śrī Caitanya Mahāprabhu.

In ecstasy, Śrī Caitanya Mahāprabhu rubbed His face against the walls all night long, making a peculiar sound, “goṅ-goṅ,” which Svarūpa Dāmodara could hear through the door.
 
Lighting a lamp, Svarūpa Dāmodara and Govinda entered the room. When they saw the Lord’s face, both of them were full of sorrow.
 
They brought the Lord to His bed, calmed Him and then asked, “Why have You done this to Yourself?”
 
Śrī Caitanya Mahāprabhu replied, “I was in such anxiety that I could not stay in the room. I wanted to go out, and therefore I wandered about the room, looking for the door.
“Unable to find the door, I kept hitting the four walls with My face. My face was injured, and it bled, but I still could not get out.”
 
In this state of madness, Śrī Caitanya Mahāprabhu’s mind was unsteady. Whatever He said or did was all symptomatic of madness.
 
Svarūpa Dāmodara was very anxious, but then he had an idea. The following day, he and the other devotees considered it together.

After consulting with one another, they entreated Śrī Caitanya Mahāprabhu to allow Śaṅkara Paṇḍita to lie down in the same room with Him.
Thus Śaṅkara Paṇḍita lay at the feet of Śrī Caitanya Mahāprabhu, and the Lord placed His legs upon Śaṅkara’s body.
 
Śaṅkara became celebrated by the name “the pillow of Śrī Caitanya Mahāprabhu.” He was like Vidura, as Śukadeva Gosvāmī previously described him.
 
“When submissive Vidura, the resting place of the legs of Lord Kṛṣṇa, had thus spoken to Maitreya, Maitreya began speaking, his hair standing on end due to the transcendental pleasure of discussing topics concerning Lord Kṛṣṇa.”
PURPORT-This is a quotation from Śrīmad-Bhāgavatam (3.13.5).
Śaṅkara massaged the legs of Śrī Caitanya Mahāprabhu, but while massaging he would fall asleep and thus lie down.
He would lie asleep without a covering on his body, and Śrī Caitanya Mahāprabhu would get up and wrap him with His own quilt.
 
Śaṅkara Paṇḍita would always fall asleep, but he would quickly awaken, sit up and again begin massaging the legs of Śrī Caitanya Mahāprabhu. In this way he would stay awake the entire night.
Out of fear of Śaṅkara, Śrī Caitanya Mahāprabhu could neither leave His room nor rub His lotuslike face against the walls.
 
This pastime of Śrī Caitanya Mahāprabhu’s has been described very nicely by Raghunātha dāsa Gosvāmī in his book known as Gaurāṅga–stava-kalpavṛkṣa.