[broksaksaak]

Then he uses a simile to emphasize how such a developed, cultivated mind is unspoiled and unaffected by physical tragedies.

From this, maybe it can be of some help to quote this sutta just to give some context to the Mahanama Sutta:

[...]what is the distinction, the diversity, the difference that exists herein between a well-taught noble disciple and an untaught worldling?

"When an untaught worldling is touched by a painful (bodily) feeling, he worries and grieves, he laments, beats his breast, weeps and is distraught. He thus experiences two kinds of feelings, a bodily and a mental feeling.

[...]

"But in the case of a well-taught noble disciple, O monks, when he is touched by a painful feeling, he will not worry nor grieve and lament, he will not beat his breast and weep, nor will he be distraught. It is one kind of feeling he experiences, a bodily one, but not a mental feeling.

[...]

"This, O monks, is the distinction, the diversity, the difference that exists between a well-taught noble disciple and an untaught worldling."

Sallatha Sutta