This, from a unsent addenda of a letter JRR Tolkien to Rhona Beare in October 1958, colors "The Silmarillion" (published posthumously in 1977 from stories JRRT had been writing since 1914) Chapter 2 "Of Aulë and Yavanna" comparing "Christian Mythology" (JRRT's own phrase) "sin and the fall" to good races erring in his own stories.
Aulë, for instance, one of the Great, in a sense 'fell'; for he so desired to see the Children, that he became impatient and tried to anticipate the will of the Creator. Being the greatest of all craftsmen he tried to make children according to his imperfect knowledge of their kind. When he had made thirteen [One, the eldest, alone, and six more with six mates], God spoke to him in anger but not without pity; for Aulë had done this thing not out of evil desire to have slaves and subjects of his own, but out of impatient love, desiring children to talk to and teach, sharing with them the praise of Ilúvatar and his great love of the materials of which the world is made
The One rebukes Aulë, saying that he had tried to usurp the Creator's power; but he could not give independent life to his making. He had only one life, his own derived from the One, and could at most only distribute it. 'Behold' said the One; 'these creatures of thine have only thy will, and thy movement. Though you have devised a language for them, they can only report to thee thine own thought. This is a mockery of me.'
I notice dialogue differences and a few additional facts in this version of the story: "mockery", "thirteen", and later, "laughter".
Then Aulë in grief and repentance humbles himself and asked for pardon. And he said; "I will destroy these images of my presumption, and wait upon thy will.' And he took a great hammer, raising it to smite the eldest of his images; but it flinched and cowered before him. and as he withheld his strike, astonished, he heard the laughter of Ilúvatar.
'Do you wonder at this?' he said. 'Behold! thy creatures not live, free from thy will! For I have seen thy humility, and taken pity on your impatience. Thy making I have taken up into my design.'
This is the Elvish legend of the making of the Dwarves; but the Elves report that Ilúvatar said thus also: 'Nonetheless, I will not suffer my design to be forestalled: thy children shall not awake before mine own." And he commanded Aule to lay the fathers of the Dwarves severally in deep places, each with it's mate, save Dúrin the eldest who had none. There they should sleep long, until Ilúvatar bade them awake. Nonetheless there has been for the most part little love between the Dwarves and the Children of Ilúvatar. and of the fate the llúvatar had set upon the children of Aulë beyond the circles of the world Elves and men know nothing, and if Dwarves know they do not speak of it.
And one more later paragraph, marginalia to Colonel Worskett in September 1963
No one knew where the Ents came or first appeared. The High Elves said the the Valar did not mention them in the 'Music'. But some (Galadriel) were of the opinion that when Yavanna discovered the mercy of Eru to Aulë in the matter of the Dwarves, she besought Eru (through Manwë) asking him to give life to things made of living things not stone, and that the Ents were either souls sent to inhabit trees, or else that slowly took the likeness of trees owing to their inborn love of trees. (Not all were good [illegible word]) Then Ents thus had mastery over stone. The males were devoted to Oromë, but the Wives to Yavanna.
Nice to find answers about ent-wives, dwarf-wives, and the laughter of The One.