Why a Sotapanna is Better off than any King, Emperor, or a Billionaire

Regarding the post: “Why a Sotapanna is Better off than any King, Emperor, or a Billionaire“,
a reader has asked me for the Tipitaka references for the following statements that I made:

1. “One time the Buddha was crossing a paddy field with 500 bhikkhus where many cattle were grazing, and smiled…”

and

2. ” Another time the Buddha and Ven. Ananda were walking and saw a piglet by the roadside, … “

These appear in #4 of the post. Both those animals had cultivated higher jhanas in their past human lives.

Another question is: “is there is any sutta that explains that Sotapanna does not need a teacher?”. Again, there must be several suttas.

In the early days of the website, I did not provide that many references, and I try to do that more these days. I do not remember the two suttas, and may need to spend some time looking for them. If someone knows the answer, please post the name(s) of the suttas. Thank you!