Wahdat Al-Wujood is a claim which means in Arabic (The Oneness or unity of the existence) . It claims that every thing in the existence is one or from one nature including the Creator and His creation. This claim did not come in Quran or any authentic Hadeeth , on the contrary, we read in Quran clear verses which refute this claim e.g. (ليس كمثله شيء
)Nothing is like Him (Allah)( Sura 42, Verse 11)
Ameerul Mo’minen Ali (AS) says in Du’a Al-Sabaah (The supplication of the morning): يا من دل على ذاته بذاته وتنزه عن مجانسة مخلوقاته (O He who guided to Himself and proved Himself by Himself, and He is absolutely High from homogenizing or being similar to His creatures ).
This claim of Wahdat al-Wojood existed among old non Muslims, then it was taken by some Muslims who are away from Ahlul Bayt (AS)
Ibn Arabi who is a famous Sufi (died in Damascus 638 Hjri) was among the first who mentioned the term What al-Wojood.
Some scholars say that Ibn Arabi is the founder of this term among Muslims. Some Shia scholars mentioned this term under certain meaning, but all our Shia scholars reject the claim of unity or similarity between the Creator and His creatures.