S. R. Faruqi:

In the first line there are four complete sentences, and in the second line there are four nouns. The metrical balance is very fine, but in the second line the ambiguity of apnā is finer:

1) After all, Mir is your own.
2) After all, this isn't someone else, it's your very own same old Mir.
3) After all, Mir is his own (the speaker's) sympathizer.
4) After all, Mir endures his own grief.
5) After all, this is Mir, the very one who sympathizes with everyone.
6) After all, who is Mir? In himself alone he's lamentation.
7) After all, it's because of himself alone that Mir laments or doesn't lament.
8) Even if Mir is sick, after all he belongs to himself.
9) Mir is in himself his own sick person.

Between the two parts of the second line, the word phir has been very well used for emphasis. In the same way, in the first line too the first three sentences give the pleasure of graduated sequence. 1) Always show mercy. 2) The result of this will be that you will always show kindness to him. 3) The form of the kindness will be that you will always ask about him.

It's possible that Mir might have learned this principle from the martyred Mirza Maz'har Jan-janan. This closing-verse of his,

koʾī āzurdah kartā hai sajan apne ko hai z̤ālim
kih daulat-ḳhvāh apnā maz̤har apnā jāñ-janāñ apnā

[does anyone make her lover sorrowful? She is cruel to her own self
for the well-wisher is her/his own, Mazhar is her/his own, the 'Dearest of the dear' is her/his own]

Qa'im Chandpuri has directly taken up Mirza Maz'har Jan-janan's theme:

qāʾim se koʾī ho hai ḳhafā
bandah ḳhādim-e daulat-ḳhvāh

[alas, if anyone would be angry with Qa'im!
the slave is a well-wishing servant]

But in Qa'im's verse there's neither the beauty of meaning that's in Mir's, nor the grammatical dexterity that's in Mirza Maz'har's verse.

FWP:

SETS == REPETITION; SUBJECT?
MOTIFS == SOUND EFFECTS
NAMES
TERMS

Here the two possibilities of apnā are exploited to the fullest. Since 'Mir' is the obvious grammatical subject of the second line, the four occurrences of apnā in the second line should straightforwardly mean 'his' (Mir's). But since the first line sets up an address to the beloved and contains enjambment, it's also quite possible to take any or all of the four of them as short for terā apnā , 'your own'-- with complex permutations that include those traced out by SRF.

SRF describes the phir as offering emphasis, but it also can suggest temporal and/or causal sequence. Thus the suggestion would be that if the beloved is cruel to her own Mir, who is her own sympathizer, then the resulting lamentation will also be her own fault, and the resulting sick person (whom her cruelty has struck down) will also be her own to bother about.

The amount of rhythmic repetition in the verse is also surprising and effective. The 'Hindi meter' of the verse is particularly flexible. The three symmetrical kiyā kar phrases create one pattern in the first line, while the repetitions of apnā in the second line create a whole different feel, which is enhanced by the internal rhyme of ḳhvār , zār , bīmār . The whole verse becomes hypnotic, like a chant.