Although numerology is strictly prohibited under Islam, this being AZ's 15th video released this year may be significant. Here's some (half serious) possibilities. Digit summing would indicate a call to action. 15% has been the traditional demographic resting point for Muslim conquest of a population. 15 is a multiple of the 5 pillars. The 15th Century was when the world started seeing Islam as an abomination. It was practically wiped out in the 16th century. AZ better rush out with a couple more videos before the year ends if he wants to break with historical precedence and establish that caliphate.