This proverb means that promises and plans must be put into action, otherwise they are useless. The early versions did not refer to hell or the road to hell being paved, but to hell being full of good desires, intentions, meanings, etc.
USA (New England), 1868—alternately sunny and cloudy conditions usually indicate rain—the adjective ‘shet’ is a variant of ‘shut’—it was perhaps in order to provide a rhyme for the adjective ‘wet’ that the variant ‘shet’ was chosen in the proverb
Ireland, 1809—the Wednesday before Easter—refers to the day on which Judas Iscariot formed the intent to betray Jesus—‘spy’ denotes ‘one who spies upon, or watches, a person or persons secretly’, because, from Wednesday onwards, Judas Iscariot secretly sought an opportunity to deliver Jesus to the Jewish authorities
UK, 1773—physical cleanliness betokens spiritual purity, i.e., cleanliness proceeds from piety—apparently, this phrase is erroneously ascribed to the English preacher and co-founder of Methodism John Wesley
UK, 1844—extreme meanness never made anyone better off—compare Book of Proverbs, 11:24: “There is one who scatters, yet increases more; and there is one who withholds more than is right, but it leads to poverty.”
be totally focused on your objective—USA — already well established in 1932—originated in the image of God’s watchful eye upon the sparrow, with reference to the gospel of Matthew, 10:29-32
USA, 1868—coined by U.S. critic Richard Grant White (1822-1885) to denote a word or expression whose original acceptation (preserved in U.S. English) was changed to one that he regarded as debased
UK, 1906—used by a workman asked to lift too heavy an object—‘Simpson’ chosen for its similarity with ‘Samson’, the name of a biblical hero of enormous strength
USA, 1885—humorous alteration of ‘many are called (but) few are chosen’, which refers to The Parable of the Workers in the Vineyard (gospel of Matthew, 20:1-16)