What are the examples of figurative language and rhythm in the poem "Gratitude to Old Teachers" by Robert Bly?

When employing "figurative language," writers use words and language in ways that are different from the literal meanings of the words. Metaphor and simile are two examples of figurative language. In "Gratitude to Old Teachers," Robert Bly writes about a frozen lake, which "we stride or stroll across." This poem uses figurative language, because the poet is not simply literally describing walking across a frozen lake. Rather, the frozen lake represents something else about a student's journey and the teachers that he or she learns from. In this poem, the frozen lake is a metaphor, since it represents something greater or other than a literal frozen lake.
In particular, the last line in the poem is an example of language being used figuratively:

Beneath us the teachers, and around us the stillness.

This is an example of figurative language because the teachers are not literally underneath the lake or standing beneath the students. Rather, the poet describes the teachers as "beneath us" to create a metaphor for the ways in which the students are influenced by and inspired by their former teachers.
Examples of rhythm in the poem can be found in the way the lines are broken up and the amount of syllables per line. You might try reading the poem out loud to get a sense of the rhythm of it. It might also be said that the rhythm of the poem could represent the pace of people walking across a frozen lake, one step at a time.
https://research.ewu.edu/c.php?g=53661

https://www.britannica.com/art/rhythm-poetry

This poem by Robert Bly uses an extended metaphor of a "frozen lake," representing the untraveled and possibly dangerous expanse of life stretching out in front of the young, who "walk upon the unwalked." The "old teachers," the speaker imagines, are beneath the feet of those traversing the frozen lake; the water "could take no human weight" when the speakers were "students," because they had not yet learned sufficiently to be able to set out on their own. The teachers are imagined beneath the lake because it is they who have turned it into a viable surface for the students to walk across, by equipping them with the knowledge necessary to go forward in life.
This poem is written in free verse, but it roughly conforms to iambic pentameter, with approximately five beats per line.