"The first sermon"
The Enlightened One gave his first public sermon in the Deer Park at Sarnath, near Benares, setting in motion the wheel of the dharma (or spiritual law) as he expounded the doctrine of the Four Noble Truths and the Eightfold Path. This first sermon is represented by the dharmachakra mudra, a two-handed gesture symbolizing the setting in motion of a wheel. This mudra is also used to show the Buddha in his role as a teacher.

"The Four Noble Truths"
In his first teaching, the Buddha expounded the basic doctrine of the Four Noble Truths. He first declared what he had learned the day he left the palace; namely, that suffering is universal and inevitable. In the Second Noble Truth, he explains that the immediate cause of suffering is desire. The ultimate cause of suffering, however, is ignorance concerning the true nature of reality. The Third Noble Truth encourages humanity, asserting that there is a way to dispel ignorance and relieve suffering. This path is detailed in the Fourth Noble Truth in the form of the Eightfold Path.

"The Eightfold Path"

According to the Buddha, the Eightfold path is the means to achieve liberation from suffering. Specifically, this path includes
(1) Right View
(2) Right Thought
(3) Right Speech
(4) Right Action
(5) Right Livelihood
(6) Right Effort
(7) Right Mindfulness
(8) Right Concentration