The whole verse is a marvel of affinity. 'Tear-drops' juxtaposed to 'blood of the liver'; 'both' juxtaposed to 'single'; then 'both' juxtaposed to 'night and day'. And in addition the contrast that the agitation of the heart, or the agitating of the heart, drank the blood of the liver, and because no blood remained in the liver the eyes dried up.
There's also the implication that the tears are really tears of blood, or tears mixed with blood. Thus at the time perhaps only ordinary tears are emerging, because the agitation of the heart has dried up the blood of the liver. And these ordinary tears are not worthy to be called tears.
Then, there's also the idea that for the tears to dry up is the limit of grief; Mir has used this theme repeatedly (for example, in
but here he has inserted the new idea that the day-and-night agitation of the heart has dried up the blood of the liver. Assuming that this agitation is real, by using an unconventional, or rather incoherent, kind of phrase like 'the agitation of the heart', in the second line he has created an effect of everyday life and a mood of 'dramaticness'.
In the word ;xuub there's also a small suspicion of praise; thus in addition to sarcasm there's also a mood of tranquility. He's put a lot into this verse.