This discourse is also found at SN 44.2.

This makes it clear that in this context, “realized one” cannot be just any sentient being. See note on SN 16.12:1.4.

The particle c’eva here has its normal role of slight emphasis in conjunctions, and so this phrase does not mean, “I only teach suffering and the end of suffering”. The point, rather, is that when he speaks of cessation, it is the cessation of suffering, not the cessation of an “existing being”. This saying is also at MN 75:16.1 and SN 44.2:17.13.