As this passage indicates, the “aspect of returning” refers to returning to this world to “save” all sentient beings “after being born in that land.”

Again, in the Chapter on Faith of his “Teaching, Practice, Faith and Attainment,” the Venerable Master quotes the following from Sanzengi, Zendo Daishi’s comments on the “Sutra on Meditation on (the Buddha of) Immeasurable Life”:

Further, eko refers to being born (in the Pure Land) and returning (to this shaba world), and through Great Compassion, entering the world of life and death and “teaching and transforming” (kyoka) the sentient beings here.

Here, the phrase, “being born (in the Pure Land) and returning (to this shaba world),” points out that after first being born in the Pure Land, we return to save the sentient beings in this world.

Again, the Venerable Master Shinran’s “Hymn of True Faith” contains the passage (which also appears in Master Rennyo’s “Essence of the Shoshin-ge” (Shoshinge-tai’i):

Reaching that world where lotuses are stored,
They immediately assume the body
Of suchness/dharma-nature.
Manifesting transcendent powers,
While cavorting in the forests of blind passions
They assume forms to guide others in the garden
Of birth-and-death.

As expressed here, we are born in the “world where lotuses are stored” (the Pure Land) and “assume the body of suchness/dharma-nature” (body that is Enlightened). We then return to the “garden of birth-and-death” (world of delusion because of ignorance and base passions) in order to “save” the sentient beings there.

Again, immediately following the above, is the passage:

Without fail they reach the land of immeasurable light
And universally guide sentient beings to enlightenment.
After being born in the “land of immeasurable light”
(the Pure Land) and becoming a Buddha,
They then return to “save” deluded sentient beings.