The Holy Qur’an refers to Prophet Ismail as the “Truthful in Promise,” in the following verse:
“And mention Ismail in the Book, surely he was truthful in (his) promise, and he was an apostle, a prophet.” (Surah Maryam 19:54)
Hazrat Ismail (a.s.) had promised to wait for a person, who did not turn up. Three nights passed but he still kept waiting. However, according to most of the scholars and well-known tradition the period of his wait was a whole year. During this time he also had to bear untold difficulties and sometimes survived on leaves.