SPANISH: ARABIC ORIGINS
There's a great article on Wikepedia on the Arabic influence on the Spanish language:

It's a great article with a long list of words of Arabic origin. Here are two of the most famous:
ojalá: "I hope"; "I wish that...". From law šhaʾ allāh "God willing." [11]
¡ole! (or olé): The most famous expression of approval, support or encouragement, possibly comes from wa-llah و الله, by Allah!
The list goes on and on: "aceite" (oil), "aceituna" (olive), "ajedrez" (chess), "alacrán" (scorpion), "albañil" (construction worker), "alcalde" (mayor), "algodón" (cotton)...
If you're learning Spanish, bet you didn't know you were also learning quite a bit of Arabic!
All languages are historical accidents, the product of intercultural contact and clashes.