Regarding the sutra teachings, the Buddha turned the wheel of Dharma three times during his life. The teaching in the first turning is particularly important for beginners, because at this stage most of us have only a preliminary understanding of Dharma and the contents of the first turning serves as a very good starting point. The Four Noble Truths is what the Buddha expounded in the first turning of the wheel of Dharma.

~ Khenpo's blog published on 16 July 2014