This short Dharma talk is an discussion on what to recite upon an funeral/ remebrance ceremony. Mostly (or commonly) in the ZenBuddhist society you read the Heart sutra (se Below). But i would also reccomend the "the five remembraces" from the Upajjhatthana Sutta.
The Five Remembrances (from the Upajjhatthana Sutra)
I am of the nature to grow old.
There is no way to escape growing old.
I am of the nature to have ill-health.
There is no way to escape having ill health.
I am of the nature to die.
There is no way to escape death.
All that is dear to me and everyone I love are of the nature to change.
There is no way to escape being separated from them.
My deeds are my closest companions.
I am the beneficiary of my deeds. My deeds are the ground on which I stand.
Birth will end in death.
Youth will end in old age.
Meetings will end in separation.
All things in cyclic existence are transient, are impermanent.
The Buddhas cannot wash our sins with water.
They cannot remove our suffering with their hands.
They cannot transfer their insights to us.
All they can do is teach the Dharma.
I am my own protector.
Actually as Thich Nhat Hanh put them forth in his book The Heart of the Buddha's Teaching it's only the first section that is "the five remebrances", but recommend the whole section.
As for the heart sutra it goes a little like this (the backslashes is for showing how to say it...):
The Heart of the Great Perfection of Wisdom Sutra
(Maka Hannya Haramita Shin Gyo)
A/vo/lo/ki/tes/va/ra/ Bo/dhi/satt/va/, A/wa/kened/ One/ of/ Com/pas/sion/,
In/ Praj/na/ Pa/ra/mi/ta/, the/Deep/ Prac/tice/ of/ Per/fect/ Wis/dom/
Per/ceived/ the/ emp/ti/ness/ of /all /five /con/di/tions/,
And/ was/ free/ of/ suf/fer/ing/.
O/ Sha/ri/pu/tra/, form/ is/ no/ o/ther/ than/ emp/ti/ness/,
Emp/ti/ness/ no/ o/ther/ than/ form/;
Form/ is/ pre/cise/ly/ emp/ti/ness/, emp/ti/ness/ pre/cise/ly/ form/.
Sen/sa/tions/, per/cep/tions/, for/ma/tions/ and/ con/scious/ness/ are/ al/so/ like/ this/.
O/ Sha/ri/pu/tra/, all/ things/ are/ ex/pres/sions/ of/ emp/ti/ness/,
Not/ born/, not/ des/troyed/, not/ stained/, not/ pure/;
Nei/ther/ wax/ing/ nor/ wan/ing/.
Thus/ emp/ti/ness/ is/ not/ form/; not/ sen/sa/tion/ nor/ per/cep/tion/,
not/ for/ma/tion/ nor/ con/scious/ness/.
No/ eye/, ear/, nose/, tongue/, bo/dy/, mind/;
No/ sight/, sound/, smell/, taste/, touch/, nor/ ob/ject/ of/ mind/;
No/ realm/ of/ sight/, no/ realm/ of/ con/scious/ness/;
No/ ig/no/rance/, no/ end/ to/ ig/no/rance/;
No/ old/ age/ and/ death/,
No/ ces/sa/tion/ of/ old/ age/ and/ death/;
No/ suf/fer/ing/, nor/ cause/ or/ end/ to/ suf/fer/ing/;
No/ path/, no/ wis/dom/ and/ no/ gain/.
No/ gain/ - thus/ Bod/dhi/satt/vas/ live/ this/ Praj/na/ Pa/ra/mi/ta/
With/ no/ hin/drance/ of/ mind/ -
No/ hin/drance/ there/fore/ no/ fear/.
Far/ be/yond/ all/ de/lu/sion/, Nir/va/na/ is/ al/rea/dy/ here/.
All/ past/, pre/sent/ and/ fu/ture/ Budd/has/
Live/ this/ Praj/na/ Pa/ra/mi/ta/
And/ re/al/ize/ su/preme/ and/ com/plete/ en/light/en/ment/.
There/fore/ know/ that/ Praj/na/ Pa/ra/mi/ta/
Is/ the/ sac/red/ man/tra/, the/ lu/min/ous/ man/tra/,
the/ sup/reme/ man/tra/, the/ in/com/pa/ra/ble/ man/tra/
by/ which/ all/ suf/fe/ring/ is/ clear/.
This/ is/ no/ o/ther/ than/ Truth/.
There/fore/ set/ forth/ the/ Praj/na/ Pa/ra/mi/ta/ man/tra/.
Set/ forth/ this/ man/tra/ and/ pro/claim/:
Gate! Gate! (Already Gone, Gone)
Paragate! (Already Gone Beyond)
Parasamgate! (Already Fully Beyond)
Bodhi! Svaha! * (Awakening, Rejoice)
But what the both texts really say is everything change, or do they?
May the force be with you