Poverty of Prophet Muhammad

1) 
By Allah, if they put the sun on my right and
the moon on my left to leave this matter, I
would not, until Allah shows me otherwise or I
die trying for its sake. (Ibn Hisham, As-Sirah
an-Nabawiyyah, Volume 1, page 265)

2) Muhammad pbuh paid Muslims' debt inspite of being needy:

bukhari Volume 3, Book 37, Number 495
Narrated Abu Huraira:
Whenever a dead man in debt was brought to
Allah's Apostle he would ask, "Has he left
anything to repay his debt?" If he was informed
that he had left something to repay his debts,
he would offer his funeral prayer, otherwise he
would tell the Muslims to offer their friend's
funeral prayer. When Allah made the Prophet
wealthy through conquests , he said, "I am
more rightful than other believers to be the
guardian of the believers, so if a Muslim dies
while in debt, I am responsible for the
repayment of his debt, and whoever leaves
wealth (after his death) it will belong to his
heirs."

3) poverty of prophet Muhammad pbuh,

Muslim, Book 009, Number 3507
I visited Allah's Messenger (may peace be upon
him), and he was lying on a mat. I sat down
and he drew up his lower garment over him
and he had nothing (else) over him, and that
the mat had left its marks on his sides. I
looked with my eyes in the storeroom of
Allah's Messenger (may peace be upon him). I
found only a handful of barley equal to one sa'
and an equal quantity of the leaves of Mimosa
Flava placed in the nook of the cell, and a
semi-tanned leather bag hanging (in one side),
and I was moved to tears (on seeing this
extremely austere living of the Holy Prophet),
and he said: Ibn Khattab, what wakes you
weep?
I said: Apostle of Allah, why should I not shed
tears? This mat has left its marks on your sides
and I do not see in your storeroom (except
these few things) that I have seen; Caesar and
Chosroes are leading their lives in plenty
whereas you are Allah's Messenger. His chosen
one, and that is your store! He said: Ibn
Khattab, aren't you satisfied that for us (there
should be the prosperity) of the Hereafter, and
for them (there should be the prosperity of)
this world? I said: Yes.

4) Muhammad pbuh chose a life of poverty:

Saheeh Bukhari, Volume 4,
Book of One-fifth of Booty to the Cause of
Allah, Hadith number 326, 
Umar ibn
Al Khattab says "So this property was
especially given to Allah's Apostle, but, by
Allah, neither did he take possession of it
and leave your, nor did he favour himself
with it to your exclusion, but he gave it to
all of you and distributed it amongst you till
this property remained out of it. Allah's
Apostle used to spend the yearly expenses of
his family out of this property and used to
keep the rest of its revenue to be spent on
Allah's Cause. Allah's Apostle kept on doing
this during all his lifetime."

5) disciples' witness over his poverty:

Muslim, Volume 7, Number 324
Narrated Abu Hazim:
I asked Sahl bin Sad, "Did Allah's Apostle ever
eat white flour?" Sahl said, "Allah's Apostle
never saw white flour since Allah sent him as
an Apostle till He took him unto Him." I asked,
"Did the people have (use) sieves during the
lifetime of Allah's Apostle?" Sahl said, "Allah's
Apostle never saw (used) a sieve since Allah
sent him as an Apostle until He took him unto
Him," I said, "How could you eat barley
unsifted?" he said, "We used to grind it and
then blow off its husk, and after the husk flew
away, we used to prepare the dough (bake)
and eat it."

Book 024, Number 5185:
A'isha reported that the pillow on which
Allah's Messenger (may peace be upon him)
reclined was of leather stuffed with palm fibre.

6) Muhammad pbuh helped his wives in household works:

Muhammad
(peace be upon him) used to milk his goat,
mend his clothes, repair his shoes, help with
the household work, (Musnad Ahmad, Hadith
number 23606 and declared authentic by
Shaykh Albani in Saheeh Al Jaami' , Hadith
number 4937)