What is the ruling on vowing to name a male newborn after a deceased grandfather, if the vow was written and not verbal? Is expiation obligatory, or must the vow be fulfilled? And what is the ruling on burying the placenta in a non-Islamic country?

The validity of a vow made in writing is a matter of scholarly disagreement. The Shafi'is hold that it is valid if accompanied by intention, whereas the Hanbalis are of the view that it is only valid if expressed verbally.

In the case of vowing to name a child after a specific person, this falls under the category of a permissible vow. The majority of scholars believe that a permissible vow is not binding and entails no obligation. Therefore, there is no obligation to fulfill this vow, nor is an expiation for breaking an oath (kaffarat yamin) required.