"Mama and Her Bible" joke

Four brothers left home for college and they became
successful doctors and lawyers and prospered.
Some years later, they chatted after having dinner
together. They discussed the gifts they were able
to give their elderly mother who lived in another
city. The first said, "I had a big house built
for Mama."
The second said, "I had a hundred thousand dollar
theater built in the house." The third said,
"I had a Mercedes dealer deliver an SL600 to
her."
The fourth said, "You know how Mama loved reading
the Bible and you know she can't read anymore because
she can't see very well. I met this preacher who told
me about a parrot that can recite the entire Bible.
It took twenty preachers 12 years to teach him. I
had to pledge to contribute $100,000 a year for twenty
years to the church, but it was worth it. Mama just
has to name the chapter and verse and the parrot will
recite it."
The other brothers were impressed.
Mama wrote: "Milton, the house you built is
so huge. I live in only one room, but I have to clean
the whole house. Thanks anyway." "Michael,
you gave me an expensive theater with Dolby sound,
it could hold 50 people, but all my friends are dead,
I've lost my hearing and I'm nearly blind. I'll never
use it. Thank you for the gesture just the same."
"Marvin, I am too old to travel. I stay at home
and I have my groceries delivered, so I never use
the Mercedes. The thought was good. Thanks."
"Dearest Melvin, you were the only son to have
the good sense to give a little thought to your gift.
The chicken was delicious. Thank You."