The /ð/ sound is spelled with <th> or <the>. Notice how owe appears twice, in the plural contrasting with oaths and in the singular with though.
As /ð/ is fairly rare, only occurring in 593 words in the dictionary, this was an easy list to work out manually. The contrast is not a source of difficulty where it occurs at the start of the syllable, but is much harder when syllable-final, even for native speakers.
The density value is 11.3%. The list makes 49 semantic distinctions, a loading of 73%.
bathe bay bathes bays bathed bayed bathe bey bathes beys baths baas baths bars blithe Bligh booths boos booths booze breathes breeze burthen burn burthens burns clothes close Hythe hi Hythe high lathe lay lathes lays lithe lie loathe low loathes lows loathing lowing Lytham limb oaths owes paths parse paths parse rhythm rim rhythms rims scythed side scythes sighs scythes size seethe sea seethes seas seethe see seethes sees seething seeing seethed seed sheathe she soothe Sue swathe sway swathes sways teethe tea teethes teas teethe tee teethes tees teething teeing theethed teed than Ann that at their air theirs airs their heir theirs heirs their ere there e'er their Ays them em then en these ease though owe thus us thy eye thy I truths trews writhe rye writhe wry youths use
John Higgins, Shaftesbury, December 2010.