The ruling on praying in a mosque built by a disbeliever and building a mosque on land donated by a disbeliever

The questioner:
Honorable Shaykh, may Allah grant you success, is it permissible to pray in a mosque that a disbeliever built at his own expense?

The Shaykh:
There is no harm in that, provided he has no ulterior motive or call to his religion. If his wealth is free of such motives, there is no harm in praying in it.

The questioner:
And is it permissible to build a mosque on it?

The Shaykh:
If it was built with forbidden wealth, such as riba (usury or interest), gambling, or the like, then no, one does not pray in it. However, if it was built with pure wealth, one does not pray in it only if the builder has an ulterior motive, such as calling to disbelief or the like. Yes.

The questioner:
Is it permissible to build a mosque on land donated by a disbeliever?

The Shaykh:
There is no harm, except if they have a bad motive, in which case no. Yes.