"It is one of several veins, taking blood from the head indirectly to the heart. The major ones are the right and left internal jugular veins, which arise from the base of the brain and pass down the sides of the neck, where they join the right and left brachiocephalic veins.
The word habl al-warid (jugular vein) is occurred once in the Koran: "We are nearer to him than the jugular vein" (50:16). This vein (irq) is in the depth of the heart (jauf al-qalb), and the meaning of the above verse is interpreted that "He is nearer to the heart than that vein". The only Koranic reference which carries blood away from and to the heart is the word habl al-warid, means jugular vein. Baidawi (d. 716/1317) writes that, "God knows everything about humans and this knowledge encompasses all details about the individual. Thus, God is closer to the individual than even the most intimate living person." The Koran further says: "He is in your self (anfusikum) and you do not observe" (51:21).
In a hadith al-kudsi, God says, "If My servant draws nearer to Me by a handsbreath, I draw nearer to him an arm-length, and if he draws near to Me by an arms-length, I draw nearer to him a fathom. And he come to Me walking, I come to him running." (Masnad: 3:122)
Tabari (3:480) related on the authority of Hasan al-Basri that a man asked the Prophet, "Is our Lord near that we can pray to Him in private or is He far that we cannot cry out to Him?" On that occasion, the Koranic verse revealed: "If my servants ask you concerning Me, certainly I am near. I answer the prayers of the suppliant when he calls upon Me. Let them therefore answer My call and have faith in Me that they
may be rightly guided." (2:186)