All perfect praise be to Allaah, The Lord of the Worlds. I testify that there is none worthy of worship except Allaah, and that Muhammad, sallallaahu ‘alayhi wa sallam, is His Slave and Messenger.
It is correct that Jibreel (Gabriel) is the one who hit the earth with his heel. This is what is authentically reported in Saheeh Al-Bukhari and its wording is: “And she (Haajar, mother of Ismaa‘eel [Ishmael]) saw an angel at the place of Zamzam, digging the earth with his heel (or his wing), till water flowed from that place.”
In another narration reported also by Al-Bukhari: “Jibreel hit the earth with his heel like this (Ibn ‘Abbaas hit the earth with his heel to illustrate it), and so the water gushed out.”
Al-Haafith Ibn Hajar said in Fat'h Al-Baari: “And in the narration of Ibn Jurayj: “Jibreel hit the earth with his foot,” and in the Hadeeth of ‘Ali: “Then he dug the earth with his finger and thus the water gushed out.” Ibn Is-haaq said in his narration: “Scholars claim that they always heard that it (the Well of Zamzam) was the dent of Jibreel.”
Finally, we did not find any authentic narration that indicates that Ismaa‘eel is the one who hit the earth with his foot.
Allaah Knows best.