the prohibition is general. Thus, using usurped water for ritual purification, washing clothes, drinking, or anything else is forbidden.
If he prays while in a state of ritual impurity, his prayer is invalid, because this entails neglecting an obligation and committing what is prohibited, for the Prophet, peace and blessings be upon him, said: “There is no prayer without purification.” (1)
If he prays in a graveyard, his prayer is invalid, because there is a specific prohibition concerning it. The Prophet, peace and blessings be upon him, said: “All the earth is a place of prayer except graveyards and bathhouses.” (2)
If he prays facing a grave—that is, making the grave his qiblah—his prayer is invalid, because the prohibition concerns the prayer itself. The Prophet, peace and blessings be upon him, said: “Do not pray facing graves.” (3)
His statement: “If he has intercourse in the private part, his i'tikaf is invalidated.”
From this, it is understood that if he has intercourse other than in the private part—for example, if he engages with his wife between her thighs—his i'tikaf is not invalidated. They said: unless he ejaculates, because what is forbidden is intercourse itself, whereas its preliminaries are forbidden as preventive means.
Question: If, upon entering the place of i'tikaf, he stipulated that he would have intercourse with his wife