What is the ruling on naming a newborn Ayla or Aila?

The name "Ayla" is foreign; it is not known in Arab lands, nor is its meaning in its own language understood. There are two possibilities: First: It might be specific to disbelievers, in which case it is forbidden to name a child with it, due to the prohibition of imitating them, as stated by Ibn Al-Qayyim. Second: If it is free from any Sharia (definition)-related prohibition and is common in your region among Muslims and non-Muslims alike, then there is no harm in it. However, it is generally preferable for a Muslim, and especially for an Arab, to use known Arabic names because of their good meanings and connection to the Arabic language, and to avoid imitating non-Muslims.