Swiftfoot Boots
Artifact — Equipment
Equipped creature has hexproof and [[ keyword: "haste" ]].
Equip 
"There is great wisdom in rushing headlong into combat . . . if you're prepared." —Kenjek, captain of the Thousand Swords
Svetlin Velinov
Bloomburrow Commander (BLC)
• #286Rulings
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)