Is the marriage contract valid if it was conducted in the mosque with two unknown witnesses, without agreement on the dowry, and with the two parties neither prepared for marriage nor announcing the marriage?

The majority of scholars are of the opinion that a guardian (wali) is a condition for the validity of marriage, and that a woman's marriage without a guardian is invalid, regardless of whether she is young or old, virgin or previously married. The woman's guardian is her father, then her paternal grandfather, then her son, then her brother, then their sons, then her paternal uncles.

If a woman does not have a suitable guardian, the Muslim judge marries her, based on the saying of the Prophet, peace be upon him: "The ruler is the guardian of whoever has no guardian." If the presence of a Muslim judge is impossible, then it is permissible for a Muslim man to marry her with her permission. As for announcing the marriage, it is recommended according to the majority of scholars, but not obligatory.

Therefore, if a woman has no suitable guardian and no Sharia judge in the country, then the contract performed by the Imam of the mosque between her and the man is valid if it fulfills the conditions for the validity of the contract, namely offer and acceptance and the testimony of two just witnesses.