Dear Yong Peng,

> I agree that satthudhammo is a Tappurisa, as in
> satthuno-dhammo. But, what about di.t.thapubba and
> sutapubba? I can't understand why they are Tappurisa. Please
> advise.

I understand di.t.thapubba and sutapubba to be
sattamii-tappurisa, to be analysed as, pubbe di.t.tho, "seen
in the past" or "that which was seen in the past," and pubbe
suto, "heard in the past" or "that which was heard in the
past."

We can see an example of this in the Vinaya texts'
discussion of ordination. After Angulimaala had been given
the going forth, the Mahaavagga reports that....

manussaa passitvaa ubbijjantipi, uttasantipi, palaayantipi,
a~n~nenapi gacchanti, a~n~nenapi mukha.m karonti, dvaarampi
thakenti

"Having seen [Angulimaala], people became frightened, then
became alarmed, then fled, then went by a different [way],
then veered in another [direction], then closed the door."
(Vin. i. 74)

Buddhaghosa, in his comment on _manussaa passitvaa_,
remarks:

yehi gihikaale di.t.thapubbo ye ca "aya.m so!" ti

"It's him!" [said] those by whom [Angulimaala] had been seen
before in his time as a householder."
(Vin. v. 997)

The thera Jaagara of Ava, in his Vinaya sub-commentary, glosses
Buddhaghosa's _di.t.thapubbo_ thus:

_di.t.thapubbo_ ti a`ngulimaalo pubbe di.t.tho

_di.t.thapubbo_ ('seen before') means Angulimaala seen in
the past.
(Pac.y. 3/91)

I suppose one might also take di.t.thapubba as being a
visesanapubbapada kammadhaaraya:

[tena] di.t.tho pubbo, "the pus that has been seen [by him]".

But this doesn't seem a likely construal in the context of
Exercise 20-A. :-)

Best wishes,

Dhammanando