Sayyid us-Sajideen: The Leader of Those Who Prostrate

One day Imam Zaynul-‘Aabideen (as) asked his companion Abu Hamza Thumali, “Which place is the best?”
Abu Hamza was perplexed. Not knowing what to answer, he said, “Allah and His messenger know best”.
Thereupon, the Imam (as) answered,
“The best place is that, which is between the corner of the Ka’bah and the standing place of Ibrahim. (i.e. Hajar-e-Aswad and Maqaam-e-Ibrahim). Noah lived among his people for 950 years.
If a man lived as long as Noah did, fasted by day, stood in prayer by night in this place, and met Allah without showing friendship towards us, all these would be of no use to him”. (The Life of Imam Zaynul-‘Aabideen)

Sayyid us-Sajideen
One of the many titles of this great Imam (as) was that of "Sayyid us-Sajideen" which means ‘the leader of those who prostrate’. In fact, it is reported that he (as) prostrated so much that he was called ‘Dhut-Thafanaat’.
Thafanaat in Arabic means ‘Calluses’. He was called this because something like the calluses of the camel appeared on the parts on which he prostrated.
Imam Muhammad al-Baqir (as) has said, “My father used to get calluses on the places on which he prostrated. He used to cut them at least twice in a year. Every time he had to cut five such calluses hence he became known as Dhut-Thafanaat (One with calluses or lumps)”. (Bihar al-Anwaar)
It would be important to mention here that this is one of the characteristics of a true and sincere believer. Allah (SWT) Himself has praised such people in the Holy Quran.
“Muhammad (S.A.W.) is the messenger of Allah; and those who are with him are severe against the infidels but compassionate among themselves. You will see them bowing and prostrating, seeking His grace and pleasure; Their mark is on their faces (foreheads) from the effect of prostrations”. (48:29)
It is also reported from the Imam Baqir (as) that:
“Whenever my father ‘Ali ibn al-Husayn (as):
-Remembered any bounty of Allah, he (as) prostrated.
-Read any verse of Quran with Sajdah, he (as) prostrated.
-He completed his obligatory prayer, he (as) prostrated.
-He made peace between two people, he (as) prostrated.
The marks of prostrations were all evident on his parts of body used for Sajdah, thus he became known as As-Sajjad”. (Bihar al-Anwaar)
It is also reported that:
[Once our Imam (as) went to the desert. One of his slaves followed him and saw that the Imam (as) was prostrating on a coarse stone and reciting:
LAA ILAAHA ILLALLAHU HAQQAN HAQQA
LAA ILAAHA ILLALLAHU TA’BBUDAN WA RIQQA
LAA ILAAHA ILLALLAHU IMAANAN WA SIDQA
By the time the Imam (as) raised his head from Sajdah, the slave had counted that our Imam (as) had recited all these for 1000 times.] (Bihar al-Anwaar)