"St. Augustine says that God will cause those who in this life have most succored those holy souls, when they come to purgatory themselves, to be most succored by others. l may here observe that, in practice, one of the best suffrages is to hear Mass for them, and during the Holy Sacrifice to recommend them to God by the merits and passion of Jesus Christ. The following form may be used:
'Eternal Father, I offer you this Sacrifice of the Body and Blood of Jesus Christ,
with all the pains which He suffered in His life and death;
and by His passion I recommend to you the souls in purgatory,
and especially that of...' etc.
And it is a very charitable act to recommend, at the same time, the souls of all those who are at the point of death."
~ St. Alphonsus Liguori ~