Figures of speech, otherwise known as literary devices, are very common in poetry. Commonly used figures of speech in poetry are similes, metaphors, alliteration, assonance, personification, and hyperbole.
A metaphor is the comparison of two things not using the words "like" or "as" in the line (if "like" or "as" is used, it is a similie). Alliteration and assonance are very similar as well. Alliteration is the repetition of a consonant sound, within a line of poetry, and assonance is the repetition of a vowel sound. A hyperbole is an exaggeration of something that a reader is not meant to literally accept.
This being said, in the poem "Laugh and Be Merry", there are many examples of literary devices being used.
First, a metaphor is used when Masefield compares time to a length of thread.
Another example is "So we must laugh and drink from the deep blue cup of the sky" where a hyperbole is used. Masefield is exaggerating the fact that the sky can quench man's thirst from its cup. While readers know that the sky does not posses a cup from which they can drink from, the imagery is set in regards to the fact that the sky offers an abundance of things for the soul.
Personification is also used in the line "the jubilant song of the great stars sweeping by" given human characteristics (the ability to sing) is given to the stars.
In the line "be merry, remember" alliteration takes place. The consonant sound "m" is repeated in the words 'merry' and 'remember.' The line "So we must laugh and drink from the deep blue cup of the sky" depicts assonance in the same way, but using a vowel sound- the strong 'e' in both 'we' and 'deep.'