Whenever the Prophet r has a serious matter in mind, he would rush to the prayer, because in it is the proclamation of continuous devotion and reliance on Allah U. The key to the prayer is Allahu Akbar (Allah is the greatest) and the prayer is not valid without it. Hence Allah U is greater than my ownself, my concerns, my occupations and my enemies. Allah U is greater than everything. And when a caller calls Allahu Akbar… Allahu Akbar, he is calling out the greatest call to the greatest form of worship, that is, proclaiming the continuous devotion and dependence on Allah U. So, leave everything and come to the prayer.