POLONIUS      [Reads.] Doubt thou the stars are fire,

Doubt that the sun doth move,

Doubt truth to be a liar,

But never doubt I love.

O dear Ophelia, I am ill at these numbers. I have not art
to reckon my groans, but that I love thee best, O most best,
believe it. Adieu. Thine evermore, most dear lady, whilst
this machine is to him. Hamlet.

This in obedience hath my daughter shown me;

And more about hath his solicitings

As they fell out, by time, by means and place,

All given to my ear.   (2.2.114-125)

It is a fairly terrible poem, sometimes accentuated in performance when Polonius scrupulously ensures that move and lovedo not rhyme (in early modern pronunciation they would have been closer). But it’s having a go, as far as protestations go, you can call into question all the certainties of life, including the now-disproven belief that the sun moved around the earth—but don’t ever doubt that I love you. And Hamlet knows that it’s a pretty rubbish poem, or at least pretends to admit it: O dear Ophelia, I am ill at these numbers; don’t know much about poetry, especially the technicalities of metre and rhyme. And I have not art to reckon my groans; I lack the skill to give a proper account of my suffering, even to keep tally of my sighs. But that I love thee best, O most best, believe it. All I can say, is that I love you, more than anything. You are my everything. (If Ophelia’s there, she’s got her eyes shut, or she’s staring fixedly into space, willing herself to disappear; this was written for her, no one else, and it meant—means—something, to her, no one else.) Adieu. Thine evermore, most dear lady, whilst this machine is to him. Hamlet. And I’m yours and I’m yours, for as long as I live, as long as I have life and breath, as long as my body’s mine to call my own.

There might be a pause, while Gertrude and Claudius digest this, or Polonius—having read in a monotone, even—just carries on as if he were delivering a morning briefing, another report from the ambassadors. This in obedience hath my daughter shown me, she did as she was told, I commanded her as I knew I should. And she’s told me more about his solicitings, the things he’s been saying to her, asking her to do, as they fell out, by time, by means and place, all given to my ear. She’s told me everything about Hamlet, with all the particulars, all the circumstances. Polonius casts Ophelia as a truthful, reliable witness, and himself as a loyal servant, doing everything correctly.