Swiftfoot Boots
Artifact — Equipment
Equipped creature has hexproof and [[ keyword: "haste" ]].
Equip 
"Start with small, careful steps. I've had customers accidentally jog themselves halfway across the continent in these things." —Norris, arcane cobbler
Gabor Szikszai
Foundations (FDN)
• #355Rulings
If a creature enters the battlefield under your control and gains haste, but then loses it before attacking, it won't be able to attack that turn. This means that you can't use one Swiftfoot Boots to allow two new creatures to attack in the same turn.
(wotc • 2018-03-16)
Rulings
If a creature enters the battlefield under your control and gains haste, but then loses it before attacking, it won't be able to attack that turn. This means that you can't use one Swiftfoot Boots to allow two new creatures to attack in the same turn.
(wotc • 2018-03-16)