SuttaCentral
And then Venerable Migajāla approved and agreed with what the Buddha said. He got up from his seat, bowed, and respectfully circled the Buddha, keeping him on his right, before leaving.
https://voice.suttacentral.net/scv/index.html?r=0.6739771846290665#/sutta?search=SN35.51-100
It comes from Hinduism:
“In many Hindu temples, the temple structure reflects the symbolism of the Hindu association of the spiritual transition from daily life to spiritual perfection as a journey through stages. Ambulatory passageways for circumambulation are present through which worshipers move in a clockwise direction, starting at the sanctuary doorway and moving inward toward the inner sanctum where the deity is enshrined. This is a translation of the spiritual concept of transition through levels in life into bodily movements by the worshipers as they move inwardly through ambulatory halls to the most sacred centre of spiritual energy of the deity.[6] Circumambulation is done in a clockwise direction and in an odd rather than even number of times. Circumbulatory walking around the shrine, by keeping time, is a common form of Hindu prayer. The circumbulary pathway made of stone around the shrine is called the Pradakshina path.[7]”—Wikipedia
The Sanchi stupa has an ambulatory path around it.
"Energy expands in the clockwise direction with reference to diety and hence one has to circumambulate ( Pradakshinam) in the clockwise direction inorder to be in the energy field and enables the person to absorb energy better. All ancient Temples were built and the dieties were powerfully consecrated and the people are expected to derive benefit and the temples serve as a self charging system . "—Quora
Oh I see.
I thought Buddhist circumambulation in anticlock wise.
So when they exist the Stup is on your left.
Is this your understanding?
Sorry.
Muslims circumbulate around Kaba in anticlock wise.
Buddhist circumbulate around Bodhi tree and Stupa around clockwise.
So they exit keeping Stupa in the right.
https://moonpointer.com/new/2009/11/significance-of-clockwise-circumambulation/
No. We circumambulate clockwise for various ceremonies. From the suttas this appears to be an already-established custom at the time of the Buddha.
The Buddha refutes power of circumambulation to overcome kamma:
https://www.accesstoinsight.org/tipitaka/sn/sn42/sn42.006.than.html
The fact that kamma is the focus of the sutta indicates that such practices are on the level of mundane right view (MN 117).
Sure, I understand it to be simply respectful protocol, like bowing, etc, not something magical.
It seems being on the right hand side also has some significance in Christianity.
I read somewhere it was to do with the idea the right side was clean and the left was not.
They ate with the right hand, used the left hand for bathroom duties.
Could it have to do with the way monastics wear the robe over one shoulder?
If anyone circumbulates without understanding, they will circumbulate samsara!
Is circumbulation a ritual?
Would a Sotapann a do this?
Is ‘pirit nool’, or aumlets ritualistic?
Is offering dana to the Buddha’ before noon, a ritual?
with metta,
It could also be related to the predominance of right-handed people, viewing the right-hand side as stronger or more dominant.
Just for interest (not ebts) 
In my culture (Latvian) the right hand is viewed as being the ‘better’, more useful and important hand. This is embedded in our culture to the extent that still today, when people marry, they wear wedding rings on the right hand (not the left like most others) - to show that they are giving their ‘best’ hand to their partner.
I daresay this is near culturally universal because left-handed individuals are always in the minority. I think this was the reasoning behind the now-defunct (in Canada at least) practice of training left-handed individuals to be right-handed.
Us poor left-handers suffer from not very newsworthy forms of discrimination, such as the pain of using scissors and squeezing two fingers into a space meant for a thumb, particularly frustrating in kindergarten.
Lobby!!
Latest discrimination I found and added to my list.
Let’s all use our left hands to show support! 