The Buddha stays “on message” in this passage from the Majjhima Nikaya:
Kiñca, mālukyaputta, mayā byākataṃ? ‘idaṃ dukkhan’ti, mālukyaputta, mayā byākataṃ; ‘ayaṃ dukkhasamudayo’ti — mayā byākataṃ; ‘ayaṃ dukkhanirodho’ti — mayā byākataṃ; ‘ayaṃ dukkhanirodhagāminī paṭipadā’ti — mayā byākataṃ. kasmā cetaṃ, mālukyaputta, mayā byākataṃ? etañhi, mālukyaputta, atthasaṃhitaṃ etaṃ ādibrahmacariyakaṃ nibbidāya virāgāya nirodhāya upasamāya abhiññāya sambodhāya nibbānāya saṃvattati. tasmā taṃ mayā byākataṃ. tasmātiha, mālukyaputta, abyākatañca me abyākatato dhāretha; byākatañca me byākatato dhārethā”ti.
What have I taught, Malukyaputta? I’ve taught “there is suffering,” I’ve taught “here is the cause of suffering,” I’ve taught, “here is the cessation of suffering,” I’ve taught “here is the mode of conduct that leads to the cessation of suffering.” What is my intention for teaching these things, Malukyaputta? Because they are beneficial; they are the starting point of the most excellent life; they lead to disenchantment, the end of desire, calmness, total understanding, awakening and liberation. That’s why I have taught them. And so, Malukyaputta, I have been silent on those things not fitting to teach; I have taught those things that are fitting to teach.
Cūḷamālukya Sutta, Majjhima Nikaya 63 v. 128
One of many passages in the Canon in which the Buddha refuses to answer ontological, cosmological and metaphysical questions. As this verse makes clear, the Dhamma is not a set of doctrines to be accepted and believed, but a path to be followed.