This Hadīth shows that ‘Ali ibn Abi Tālib (may Allah be pleased with him) the Prophet's cousin, got married to the Prophet's daughter Fātimah (may Allah be pleased with her). The Prophet (may Allah's peace and blessings be upon him) commanded him to give his wife a dowry so as to gladden her, and show his appreciation and desire for her. But ‘Ali could not find anything. So the Prophet (may Allah's peace and blessings be upon him) asked him to give her his armor as dowry, despite its being insufficient.