The Buddha taught in the Diamond Sutra many profound teachings. It is said to be of the "Wisdom" angle but it actually contains all the 84000 teachings of the Buddha. It is said that the first chapter itself IS the Diamond Sutra encapsulated. For your information the Diamond Sutra has 32 chapters.
Some contemplations it touches on are:
1.contemplation of the body as impure,
2.contemplation of feelings as suffering,
3.contemplation of thoughts as impermanent,and
4.contemplation of dharmas as devoid of self.
Also, the Buddha taught selflessness and the 3 poisons with the verse:
There is no mark of self,
And no mark of others,
No mark of living beings
And no mark of a life.
If we can contemplate the above verse, we can eliminate greed, anger, ignorance and desire.