A MOTHER TO HER NEW-BORN BABE

For these lines  

"I'm sure just of one thing which is l love you much,  
and ready to give you my days and all my nights."  

to make sense grammatically, they should read

I'm sure just of one thing which is l love you much,  
and (that I) am ready to give you my days and all my nights.  

You've (once again) sacrificed sense on the altar of measurement.

In any case, these lines are just cliches.  They are mundane declarations. There's no music in them,  and they are hardly memorable.  Why would anyone want to read them a second or a third time after an initial read?

There's also the problem of incoherency in your first lines.  To "veil" something is to cover something up,  not to reveal it.  So by using "veil" as if it meant "to display",  you are showing yourself (again) not very well versed in English.

1- After the coordinator AND, all the repeated items can be omitted. Therefore, we can omit [that, l, and the verb], and keep only READY...... . Go to the rules before you criticize.
2- According to reading them a second or a third time, there is an idea in the poem for the others who can understand it easily. I am sure they read them again for that idea.

"1- After the coordinator AND, all the repeated items can be omitted. Therefore, we can omit [that, l, and the verb], and keep only READY...... . Go to the rules before you criticize."

What "repeated" items?

Sorry, but what you have, according to you, is a sentence that reads "I'm sure just of one thing which is l ... ready to give you my days and all my nights .

In any case,  what's original to what you say in these lines?  How is this not cliche?

The repeated items are: 1- that or which THE RELATIVE PRONOUNS 2- I   as it is the same subject 3- am   can be omitted as it is related to the same subject. Then, we use the adjective [ ready] as l did.

I have to wonder if you know what "repeated" means.  What one thing is stated **in the same way** again and again?

I mean a word of the same part of speech, or the same function.

But you said "items".  And isn't it "wordS" of the same part of speech?

Leaving aside the question of whether the coordination of a complete thought with an incomplete thought (which is what "ready to give you my days and all my nights" is) is good grammar, not to mention that you have admitted that what you think you have actually, though implicitly,  said **is** "that I am ready to ..",  you seem to be ignoring that the real issue at hand is **not**  what it is that according to the rules of grammar can be left out of an expression that is linked to something in another expression by the use of AND, but whether the most felicitous way to express what you were trying to express is to include the words "that I am" or "I'm" at the beginning of the next thing in your catalog of the things that you are sure of if your **being**  ready to give nights and days is one of these things?    
 
And there are still the matters of whether "veil" is a good choice of words for what you are trying to convey in your first lines and whether the expressions that you use aren't riddled with cliches.

I'm wondering if you realize that when you say

"as when you smile at me, you ascertain your joy."  

you are essentially conveying this idea:

that when you smile at me, you "find out or learn with certainty" your joy.