(Spoilers for Criminal Minds "Slave of Duty" - S5 ep10 or 11)
Near the end of season 1 of Criminal Minds we learn that Hotch and Haley met due to a school production of Pirates of Penzance. So it's appropriate for him to quote from it at her funeral in season 5.
OTOH I've always thought that what he quoted was an (admittedly not entirely uncharacteristic example) of Hotch supremely missing the point. Granted, quoting from a comic opera at a funeral does limit your choices. But. As she's about to be killed, she makes Hotch promise to tell their son about how they met, how he used to make her laugh. Basically, stop walling up all his emotions as he's done increasingly over the last five years.
And so at her funeral he says he considers
Oh, dry the glistening tearto be an appropriate sentiment? Oh Hotch, we love you, but you really suck at this feelings thing.
That dews that martial cheek;
Thy loving children hear [here?]
In them thy comfort seek.
With sympathetic care
Their arms around thee creep,
For oh, they cannot bear
To see their father weep!
Anyway, today for reasons which I already forget I happened to be looking up the context of the song. (Really someday I ought to watch the DVD I have.) And discovered it's not so much a "Dear Dad, please stop grieving", it's a "Dear Dad, please stop feeling guilty (about lying)".
Which... if Hotch is (at least subconsciously) feeling guilty about that thing where he beat Haley's murderer to death with his bare hands... would explain why the quote resonated so strongly for him. I still wouldn't call it appropriate for a funeral where you should be thinking about your wife rather than your manpain, but. At least it explains it.