The reason for the revelation of this Surah has already been mentioned.Ikrimah said,"When- the Jews said, `We worship Uzayr, the son of Allah,' and- the Christians said, `We worship the Messiah (Isa), the son of Allah,' and- the Zoroastrians said, `We worship the sun and the moon,' and- the idolators said, `We worship idols,'Allah revealed to His Messenger, قُلْ هُوَ اللَّهُ أَحَدٌSay:"He is Allah, One."meaning,- He is the One, the Singular,- Who has no peer,- no assistant, no rival,- no equal and none comparable to Him.This word (Al-Ahad) cannot be used for anyone in affirmation except Allah the Mighty and Majestic, because He is perfect in all of His attributes and actions.Concerning His saying, اللَّهُ الصَّمَدُ