What images are conjured with Duncan's words in Act I, Scene 4 of Macbeth?

In Act I, Scene 4 of Macbeth, with King Duncan's words there are images of Nature and light that contrast with the imagery of the three witches in the previous scene.

Whereas in the previous scene the witches' nature is menacing and obsessive and dark, in Scene 4, the images of nature are depicted as nurturing and bountiful. Duncan states that things have occurred with such rapidity that he has been unable to reward Macbeth properly and quickly enough:

That swiftest wing of recompense is slow

To overtake thee. (1.4.18-19)

In the first line, King Duncan speaks with a metaphor for his gratitude--"That swiftest wing of recompense" (1.4.18)--that was unable to reach his noble soldier quickly enough. The image created by this figure of speech is that of a bird. To this, Macbeth replies that he has had his reward by having the honor to serve King Duncan.

In his next lines, Duncan creates the image of a garden as he says,

I have begun to plant thee..." and like the good farmer, he will labor
To make thee full of growing.(1.4.29-30)

This nature imagery continues with the suggestion of a bird when the king thanks Banquo, 

...let me enfold thee (as a bird covers her young beside her--takes her "under her wing")
And hold thee to my heart. (1.4.32-33)

Then Duncan advises Macbeth, Banquo, and the others that although he will make his son Malcolm his heir, he will reward the others:

But signs of nobleness, like stars, shall shine (1.4.42-43)

On all deservers. 

Here, then, is also light imagery with that of nature in the use of the word stars.