Praise be to Allah.
1. The Quran indicates that Y’aqub (peace be upon him) gave final instructions to his sons before he died. “… he said unto his sons, ‘What will you worship after me?’ They said, ‘We shall worship your Ilah (God — Allah) the Ilah (God) of your fathers, Ibrahim, Isma‘il, Ishaq, One Ilah (God), and to Him we submit (in Islam).’” [2:133 – interpretation of the meaning].
2. The scripture of Ibrahim (peace be upon him) is mentioned in Surat al-A’ala 87:19 (interpretation of the meaning): “The Scriptures of Ibrahim and Musa”; and in Surat al-Najm 53:36-37 (interpretation of the meaning): “Or is he not informed with what is in the Pages (Scripture) of Musa (Mose), and of Ibrahim who fulfilled (or conveyed) all that (Allah ordered him to do or convey).”
Source: Sheikh Muhammed Salih Al-Munajjid