Early in 632 C.E. in the Hajj season, the Holy Prophet decided to proceed to Makkah to perform the "Hajj". The pilgrimage was planned on a large scale, Messengers were sent to all parts of Arabia calling upon the Muslims to assemble at Madina for the purposes of the pilgrimage. In response to this call, over one hundred thousand Muslims gathered at Madina to proceed to Makkah to perform the Hajj.
"When a person dies, his works end, except for three: ongoing charity, knowledge that is benefited from, and a righteous child who prays for him."
Prophet Mohammed (PBUH)
"The best of what a man leaves behind are three: a righteous child who supplicates for him, ongoing charity the reward of which reaches him, and knowledge that is acted upon after him."
Sunan Ibn Mājah
"Every day two angels come down from Heaven and one of them says, 'O Allah! Compensate every person who spends in Your Cause,' and the other (angel) says, 'O Allah! Destroy every miser.'"
Sahih Bukhari