While the New Testament was written in Greek, scholars generally believe that Jesus primarily spoke Aramaic in his daily life. Therefore, it is highly likely that he prayed in Aramaic.
Here's a more detailed explanation:
* Aramaic: This was the common language of Judea in the first century AD. Evidence suggests that Jesus and his disciples used Aramaic in their everyday interactions.
* Hebrew: Hebrew was still used for religious texts and formal worship in the synagogues. However, it was not the primary spoken language.
* Greek: While Greek was the language of the Roman Empire and used in some areas of Palestine, it was less likely to be used by Jesus in his personal prayers.
There are specific instances in the New Testament where Jesus uses Aramaic words, such as "Talitha koum" (Mark 5:41) and "Eloi, Eloi, lama sabachthani?" (Mark 15:34), which further support the idea that Aramaic was a language he used naturally and might have used when praying.
Therefore, the most probable answer is Aramaic.