Born on April 13, 1977 in Morocco, Essabar moved to Germany in 1997, and studied medical technology in college in Hamburg in 1998. Through the Muslim religious community there he met Ramzi bin al-Shibh and other members of the Hamburg cell. Essabar quickly became more religious while in Germany. He lived for some time at the Hamburg cell apartment.
After being radicalized in 1999, Essabar trained in Afghanistan where he learned combat skills and passport alteration. Ramzi bin al-Shibh later said that Essabar delivered the cryptic message from Khalid Shaikh Mohammed, indicating the date that the September 11 attacks would be carried out, although bin al-Shibh's claim is in doubt. Essabar may not have known the significance of the date, but he did relay the message. The truth of bin al-Shibh's claims is in doubt, due to "inconsistent statements". Despite a Germanarrest warrant issued a month after the attacks, Essabar was not captured and, according to al-Qaeda, was later killed in Afghanistan.