The Sakya Buddha’s liberating insights
The Sakya Buddha’s two fundamental insights that became the necessary conditions for (i.e. that determined) his understanding of the cause of suffering and of the means to its elimination were:
“All that is subject to arising is subject to cessation.”
“A thing arises because of conditions; it ceases when the conditions for its arising cease!”
A thing (for instance, a person like you and me) emerges as transient phenomenon from causes (or conditions).
In simpler words, a thing* happens as a passing effect (i.e. as a fading event), not as a (1st, hence permanent) fixed cause. Because an effect derives from causes, it is dependent (i.e. in bondage).
Suffering (Pali: dukkha: sorrow, distress, ill etc.,.) happens not because effects/things are dependent and transient as such, but from clinging (i.e. being attached or addicted) to that which is transient and can’t be owned. In short, if I attach to something I don’t own and can’t hold on to, ‘like a ship in the night’, I’m going to get hurt.
Liberation, joy and peace (read: nirvana) are attained when one ceases clinging to that which one doesn’t own and can’t hold on to.