Francis didn’t reference any scripture… did you read the tweet? 

In the midst of the confusion and vanity of human words, we need the #WordOfGod. Scripture is the only true compass for our journey, and it alone is capable of leading us back to the true meaning of life amid so much woundedness and confusion.

We can deduce that this scripture, Is the holy inspired scripture of the Catholic Church. 

I truly don’t understand your question. He said scripture. What is that scripture.
#WordOfGod