Many accounts of the Buddha's life describe Śuddhodana preventing his son from leaving the palace to avoid a prophecy said by Asita. For example, this site says:
Suddhodana was determined to see his son become a king so he prevented him from leaving the palace grounds. But at age 29, despite his father's efforts, Siddhartha ventured beyond the palace several times.
In what sutta (of any canon or tradition) the Asita prophecy and the above events are described? The only sutta I know about Asita is Snp 3.11 but it does not mention the alternative prophecy for his future, and most suttas I know have the Buddha describing the palaces he lived in, but not his father's plans to prevent him from becoming a Buddha.
Also, it's commonly said that, after going outside the palace, he saw a sick, an old, and a dead person. Is this in the pali canon? DN 14 says Vipassi was the one who encountered these people. I only know of suttas such as AN 3.39 where it says that the Bodisatta reflected on sickness, old age and death. Do these stories got conflated?