Yes, a favorite passage:
I know that while my father, the Sakyan, was ploughing, and I was sitting in the cool shade of a rose-apple tree, aloof from pleasures of the senses, aloof from unskilled states of mind, I entered on the first meditation (concentration), which is accompanied by initial thought and discursive thought, is born of aloofness, and is rapturous and joyful, and while abiding therein, I thought: ‘Now could this be a way to awakening?’ Then, following on my mindfulness… there was the consciousness: This is itself the Way to awakening. This occurred to me…: ‘Now, am I afraid of that happiness which is happiness apart from sense-pleasures, apart from unskilled states of mind?’ This occurred to me…: I am not afraid of that happiness which is happiness apart from sense-pleasures, apart from unskilled states of mind.’
(MN 36; PTS vol I p 301; parenthetical added)
Also:
… the situation occurs, Ananda, when wanderers belonging to other sects may speak thus: ‘The recluse (Gautama) speaks of the stopping of perceiving and feeling, and lays down that this belongs to happiness. Now what is this, now how is this?’ Ananda, wanderers belonging to other sects who speak thus should be spoken to thus: ‘Your reverences, (Gautama) does not lay down that it is only pleasant feeling that belongs to happiness; for, your reverences, the Tathagatha (the “Thus-Gone One”, the Buddha) lays down that whenever, wherever, whatever happiness is found it belongs to happiness.
(MN 59; tr. Pali Text Society vol II p 69)
Yer right that:
… a good (person] reflects thus: “Lack of desire even for the attainment of the first meditation has been spoken of by [me]; for whatever (one) imagines it to be, it is otherwise” [Similarly for the second, third, and fourth initial meditative states, and for the attainments of the first four further meditative states].
(MN 113; tr. Pali Text Society vol III pp 92-94)
Gautama also said that the means of transcending the “equanimity with respect to uniformity” of the arupa jhanas was “lack of desire, by means of lack of desire”, so there you have it (not looking up the source, unless you ask for it–worn out looking 'em up!).
Still, at least in the translations of F. L. Woodward for the Pali Text Society, a certain ease arrives with the first “corporeal” jhana, and is still present in the third. Sages abide in that third state (exhausted looking up sources, but I think that’s standard). That ease disappears in the fourth state, and I have to wonder what you are referring to when you speak of “true ease”–maybe happiness, like the happiness that is still present in the cessation of volition in feeling and perceiving?
Yes, Gautama entered the first jhana watching his father plow (the king?–I think not!), and there’s no reference to “making self-surrender the object of thought, one lays hold of concentration, lays hold of one-pointedness” (as at SN 48.10, tr. Pali Text Society vol. V p 174) with regard to that. Doesn’t mean these things are not a part of finding concentration, as an adult not sitting under a rose-apple tree.