Is explicit offer and acceptance required for gifts (Hiba), presents (Hadiya), and charity (Sadaqa)?

Primary text

Explicit offer and acceptance are not transmitted as having been used in gifts, presents, or charity from the Prophet (peace be upon him) or his Companions. When gifts were brought to the Prophet (peace be upon him), he only inquired whether the item was a gift or charity to determine whether to partake in it, and in most narrations, neither offer nor acceptance was mentioned. The implied conduct (Mu'atah) and separation based on mutual consent suffice for their validity. If offer and acceptance were preconditions in these contracts, it would be difficult, and most Muslim contracts and wealth would be deemed illicit.