What are the 善知识 (spiritual guides or friends) that we hear mentioned in the Buddhist Sutras?

Master Sheng Yen gives his discourse on:
What does a “spiritual friend” mean?

Spiritual friends are both teachers and companions; they advise us, encourage us, and help us through their suggestions, through their association with us, and through their conceptual guidance. So, keeping a good friend, a spiritual friend near can develop character, increase wisdom, and facilitate peace of mind and body, a happy and harmonious family, and a smooth career.

Venerable Ru Jun talks about why and how we should depend on 善知识 (spiritual guides) and their teachings.
And that we should seek out our spiritual guides.

Starting from the 7:00 minute mark:

Venerable Ru Jun describes a story how Master Ri-Chang felt the suffering that pigs being brought to slaughter were going through and used this as motivation for himself. The pigs thus became Master’s spiritual guides.

listen from the 3:56 min mark:

Venerable Ru Jun explains how we can get close to our Spiritual Guides:


This is a reminder to me not to treat this concept of depending on the spiritual guides superficially but to try to accept the advice of my Spiritual Guides wholeheartedly.