Question:

"Allah" is the most appropriate name for God in the Qur’an. Is this name "Allah" mentioned in other religious scriptures besides the Qur’an?

Answer:

Almost all the major religious scriptures of the world contain the word "Allah" as one of the names of God.

1. Elohim El, Elah, Alah
   In the Bible, God is very often referred to as ‘Elohim’ in the Hebrew language. The ‘im’ in the ending is a plural of honour and God is referred to as ‘El’ or ‘Elah’ in the English Bible with commentary, edited by reverend C. I. Scofield. ‘Elah’ is alternatively spelled as ‘Alah’. The difference in spelling is only of a single ‘L’. Muslims spell Allah as ‘Allah’ while the Reverend has spelled it as Alah and they pronounce it as ‘Elah’. Muslims pronounce it as Allah. Hebrew and Arabic are sister languages therefore we say it should be pronounced as ‘Allah’ and not as ‘Elah’.
   
   When I was in school, I was taught ‘D, O’ is do, ‘T, O’ is to. What is ‘G, O’ It is ‘go’ and not ‘gu’. ‘N, U, T’ is nut, ‘C, U, T’ cut; ‘B, U, T’ is but, what is ‘P, U, T’? Not ‘pat’ but it is ‘put’. If you ask "Why?" The answer is "It is their language". If I have to pass I have to say ‘P, U, T’ is ‘put’ and not ‘pat’. Similarly the right pronunciation for A, L, L, A, H, is Allah.

Jesus (pbuh) cried out Allah Allah when he was put on the cross
It is mentioned in the New Testament in the Gospel of Mathew, chapter 27 verse 46 as well as Gospel of Mark, chapter 15 verse 34 when Jesus (pbuh) was put on the cross.

Jesus cried with a loud voice saying "E’-Li, E’-Li la’-ma sa-bach’-tha-ni?" that is to say, ‘My God, My God why hast Thou Forsaken Me?’ Does this sound like Jehovah! Jehovah! why has thou forsaken me? Does it sound like Abba Abba? The answer is ‘No’. Hebrew and Arabic are sister languages and if you translate "E’-Li, E’-Li la’-ma sa-bach’-tha-ni" into Arabic it is ‘Allah Allah lama tarak tani’ does it sound similar?

This statement of Jesus (pbuh), "E’-Li, E’-Li la’-ma sa-bach’-tha-ni" is preserved in its original Hebrew in each and every of its translation which is available in more than 2000 different languages of the world and in each and every of them, "Allah" is present.

2. "Allah" in Sikhism
   One of the names by which Gurunanak Sahib referred to God is "Allah".

    

3. "Allah" in Hinduism

   1. "Allah" in Rigveda Book 2 Hymn I verse II
      Even in the Rigveda which is the most sacred scripture of the Hindus, one of the attributes given to God Almighty in Book no 2 Hymn no I verse II, is ‘Ila’ which if pronounced properly is the same as Allah.

       

   2. Allo Upanishad:
      Amongst the various Upanishads one of the Upanishad is named as ‘Allo’ Upanishad in which God is referred to as "Allah" several times.
       

       

Reference:

http://www.irf.net