I'm looking for more information on this from the Hempstead town records. p. 202 (from page 105 of Liber B) "Desembar the:7 ANo 1665 Sooeld by John Tredwall of Hampsteed Twoo Nathanall Coles of oistarbay two Loatas att matinacocke the one that wase John ashmans and the othar hise one propar davadant the one in numbar :21: contaneing :44: ackars or thare aboutes more ore Lace the othar in number 28 or ther aboutes Conttaining 33 ackers ore thare a boutes By MeeTho: Hickes. Cler."
[December 7, 1665.Sold by John Tredwell of Hempstead to Nathaniel Coles of Oyster Bay two lots at Matinacock, the one that was John Ashman's and the other his own proper dividend, the one in number 21 containing 44 acres or thereabouts more or less, the other in number 28 or thereabouts containing 33 acres or thereabouts.]
BTW, I've seen John Treadwell's birthdate given as 7 Dec 1644, which would mean this land transaction took place on his 21st birthday.
I'm researching the family of Robert Ashman of Hempstead and Jamaica, and the only John Ashman I know of on Long Island at this time was Robert's son, b. abt 1635-40, but I have no other indication that they ever owned property at Oyster Bay.