Analysis of In An Illuminated Missal

I would have loved: there are no mates in heaven;
I would be great: there is no pride in heaven;
I would have sung, as doth the nightingale
The summer's night beneath the moone pale,
But Saintes hymnes alone in heaven prevail.
My love, my song, my skill, my high intent,
Have I within this seely book y-pent:
And all that beauty which from every part
I treasured still alway within mine heart,
Whether of form or face angelical,
Or herb or flower, or lofty cathedral,
Upon these sheets below doth lie y-spred,
In quaint devices deftly blazoned.
Lord, in this tome to thee I sanctify
The sinful fruits of worldly fantasy.