At Dhul Halaifa on the outskirts of Makkah, the Holy Prophet and all his followers put on the Ihram - the pilgrim's garb. The Holy Prophet gave the signal call "Labbayyak Allah hummah Labbayk" - "Here I am at your service O Lord!" This was repeated by all the one-larch persons in the congregation. The entire valley came to ring with the sound, the Muslims calling on their Lord, submitting to Him, and placing themselves at His disposal.
"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