Is it permissible to give Zakat al-mal (money) to buy oxygen cylinders as an endowment for those in need, knowing that the money has not yet completed a hawl (lunar year), but it is being given preemptively to contribute in the current circumstances?

It is permissible to hasten the giving of zakat (definition) before its due time if the wealth has reached the nisab (definition). It is not permissible to pay zakat for purchasing oxygen cylinders or doors for waqf (endowment) and ongoing charity (sadaqah (definition) jariyah); rather, it must be spent on its rightful recipients according to Islamic law. Zakat must be given to the poor person to own, so that they may spend it on themselves.