In what sutta/suttas did Buddha stated "I never admire samsara/bhava"?
The thing you are looking for is probably a misinterpretation of this passage from Maha-Parinibbana Sutta:


  ... among these five hundred bhikkhus even the lowest is a
  stream-enterer, secure from downfall, assured, and bound for
  enlightenment."
  
  
  And the Blessed One addressed the bhikkhus, saying: "Behold now, bhikkhus, I exhort you: All compounded things are subject to vanish.
  Strive with heedfulness!"
  


Handa dani bhikkhave amantayami vo: Vayadhamma sankhara appamadena sampadetha.


And this one in regards to Samsara:


  “Just as even a little dung stinks, so I do not recommend even a
  little becoming, not for so much as a finger snap”