During the period of concealment (dawr-i satr), it is known that the Ismailis had offered great sacrifices for the cause of their faith, the detail of which is not accessible. They had been severely domineered and tortured by the Abbasids, the equal of which is hardly seen in other period. Suffice it to elite here one instance: a Syrian daily news, "al-Baath" on October 28, 1966 highlighted a report that a team of workers had discovered human skulls beneath the earth while digging a location to lay a pipeline, about 150 miles north of Salamia. The exhumation was immediately suspended, and the experts were summoned from Damascus for investigation. During the excavation, about 382 human skulls were exhumed, pitching with small iron nails, emanating a trembling story of severe torture and maltreatment. One skull, for instance was pierced with 151 nails. The matter was referred to the archaeological department, and after a minute examination of two months, it had been discovered that the above location originally was an old Ismaili cemetery, belonging to the period between 150/777 and 275/900. These Ismailis had to live in the teeth of very bitterest opposition, and were tortured with heartless during brutal persecutions, who could not escape the snares of the Abbasids. Being ingrained in their faith, they would not recant even under hardest trials.
Wafi Ahmad is known to have summoned his most trusted dais, called Abu Jafar and Abu Mansur at Salamia before his death, and said in presence of his son, Taqi Muhammad that: "I bequeath the office of Imamate to this my beloved son. He is your Imam from now onwards. You take an oath of allegiance from him, and must remain faithful with him in the manner you have been with me, and obey his orders." It is said that shortly before his death, Wafi Ahmad retired into solitude and died in Salamia in the year 212/828.
Wafi Ahmad had two sons, Ahmad surnamed Taqi Muhammad and Ibrahim. Nothing is virtually known about Ibrahim, save the fact that his posterity was still living at the time of Imam al-Mahdi in Salamia and were slain by the Qarmatians in 290/902.
According to Ibn Athir (10th vol., p. 184), Khalaf bin Mulaib al-Ashhabi (d. 499/1106) had captured Salamia in 476/1084 and acknowledged the Fatimid suzerainty. There is an evidence of this in an inscription in Kufic character, dated 481/1088, on the door beam of a mosque in Salamia. In the inscription, studied extensively by Rey, Hartmann, van Berchem and Littmann, Khalaf bin Mulaib says that he has erected a shrine on the tomb of Abul Hasan Ali bin Jarir. But, the Syrian Ismailis however have traditionally regarded this tomb as that of Imam Wafi Ahmad (Abdullah bin Muhammad), calling the mausoleum locally as Makam al-Imam. Later on, Prof. Heinz Halm studied and reinterpreted the aforesaid inscription in 1980, lends support to the local Syrian Ismaili tradition by holding that the mausoleum was in all probability originally erected, about 400/1009, over the tomb of Imam Wafi Ahmad by the Fatimid commander, called Ali bin Jafar bin Falah, known as qutb ad-dawla (magnate of the state), who, after subduing the rebellion of Mufraj bin Dagfal al-Jarrah Taiy, had seized Salamia for the Fatimids and whose name also appears in the inscription, and that Khalaf bin Mulaib merely repaired the site, some four decades later, vide "Les Fatimides a Salamya" (Revue des Etudes Islamiques, LIV, 1986, pp. 133-149) by Heinz Halm.