Later Muslim tradition considered the son considered for sacrifice (not named in the Quranic account, Qur'an 57. 100-109) was Isma'il. Also related is the story of Hagar and Isma'il being sent away by Ibrahim. After they had wandered for some time, they stopped in a valley where Hagar ran to and fro between the two small hills of Sa'y and Marwa -- an action commemorated in the sa'y ("running") part of the ritual of umra. The young Isma'il discovered a spring of water, Zamzam. Isma'il is considered the ancestor of the northern Arabs, and thus of the later Arab tribes.
Isma'il (Ishmael), in Islam, is mentioned in the Qur'an as one of the prophets (Qur'an 3. 84, 4. 163), and more specifically as the son of Ibrahim (Abraham) (Qur'an 14. 39). The two are believed to have rebuilt the Ka'ba in Mecca, and instituted the rites of hajj (pilgrimage) (Qur'an 2. 127-129).