A child is crying, and the adult beside her has run out of patience but not quite out of tenderness. That tension drives the poem. The speaker sounds like a mother, judging by the kisses and the repeated "my child" and "my love". She talks a small girl out of a fit of temper, which she calls "passion". Her argument is simple: God sees everything you do, so there is no point behaving badly, and being good is the road to happiness. The central idea is that conscience begins as being watched, and that a child can be steered toward goodness by affection and by the idea of an ever-present observer at once.
The form is built to be remembered. Six quatrains rhyme ABAB, and the lines alternate between four beats and three: "My sweet little girl should be cheerful and mild" is followed by the shorter "She must not be fretful and cry!" The galloping rhythm has the lilt of a nursery song, which makes the scolding sound gentler than it is and makes the lesson easy to recite. The rhymes do some of the teaching too. "Cry" is tied to "sky", so the child's weeping is paired with the place where God lives, and "love" is tied to "above". In the fifth stanza "again" rhymes with "pain", which works if you pronounce it the way many speakers still do, and it links smiling again to the end of pain.
The poem's emotional strategy is easiest to see in the second stanza. "That dear little face, that I like so to kiss" is warm, but the rhetorical question that follows is a quiet threat: "Do you think I can love you so naughty as this, / Or kiss you, all wetted with tears?" The word "wetted" is a childlike choice, more homely than "wet", and it makes the picture concrete. The mother's affection is dangled as something the child can lose, and the child is left to work out what that would cost her.
Then the poem turns to surveillance. God sees "within and without" and "looks down, from His glory above / To notice what you are about". The phrase "what you are about" is a nursery-room expression, as if God were a very attentive nanny. The fourth stanza closes the child's possible escape routes one by one: "If I am not with you, or if it be dark, / And nobody is in the way". Each condition is a moment when a child might think she is unobserved, and each is cancelled in turn. The balanced last line, "In the night as it is in the day", seems to refuse to let the gaze blink. God is reduced to an "eye", and that single image makes the idea of watching feel unavoidable.
The final two stanzas shift from threat to coaxing. The mother argues practically that crying is itself a "terrible pain", so the child's own misery becomes evidence against her bad temper. Then "I" becomes "We'll pray", and the mother joins the child instead of standing over her. The last couplet is the most surprising: "happy as long as you live, / And happy whenever you die." The promise stretches across a whole life and past it, yet "whenever" makes death sound as ordinary as bedtime. The poem judges this a fitting thing to say to a small girl, and that tells us how closely it ties good behaviour to ultimate fate.
What makes the poem worth reading is how much it shows in so little space. It is a compact example of moral verse for children, in which rhythm, rhyme, love, fear and religion all work together to shape a conscience. Modern readers may bristle at a child being told she is watched even in the dark, and at affection that seems to depend on good conduct. Yet the tone is coaxing more than cruel, and the mother's wish to see that "dear little face" smiling again is believable. The poem is uncomfortable and tender at the same time, and that mixture is what keeps it interesting.