The headland (ἄκρα) against which the waves break without ceasing (διηνεκῶς); it stands firm (ἕστηκε), and around it the seething waters (τὰ φλεγμήναντα) are "lulled to rest" (κοιμίζεται). An image of the imperturbable soul under the blows of fortune: not to repel the blow by force, but to stand so that the storm itself subsides at one's foot. The waves — external events, others' faults, misfortunes — come on endlessly; the rock is neither moved nor harmed, and moreover it calms the waters around it: the steadfast soul does not add to the turmoil but stills it.

The image holds two thoughts: (1) the external does not harm the steadfast (DOGMAno-harm-to-virtuous) — the waves break, the rock is whole; (2) the state called for is imperturbability (TERMapatheia), freedom from TERMλύπη and fear. Kin to the "inner citadel" (inner-retreat).

04-49 — the image in pure form, opening the passage and setting the stance for the dogma that follows (to remain ἄλυπος under what strikes). The cognate series of steadfastness / the inner stronghold:

• Med. 8.48 — the mind free from passions is a citadel (ἀκρόπολις): there is no more secure refuge to which to retreat;
• Med. 4.3 — the "retreat" into oneself as the most untroubled refuge (see inner-retreat);
• the contrast: to be "crushed by the present" (θραυόμενος, 04-49) — what the rock never is.

In 04-49 the rock opens the practice of steadfastness and prepares the dogma "not a misfortune, but to bear it nobly is good fortune." It serves the discipline of assent / desire: imperturbability. Unlike the river of time (flux) and the ripe olive (gracious departure), here the stress falls on unmoving firmness — to stand, rather than to flow or to fall. Connections: DOGMAno-harm-to-virtuous (the waves do not harm the rock), inner-retreat (the inner stronghold).