Hadith: Do not supplicate against yourselves, do not supplicate against your children, and do not supplicate against your property, lest you do it at a time in which Allah answers all supplications so you will be granted what you asked for

عن جابر بن عبد الله رضي الله عنهما مرفوعاً: «لا تدعوا على أنفسكم؛ ولا تدعوا على أولادكم، ولا تدعوا على أموالكم، لا توافقوا من الله ساعة يُسأل فيها عطاءٌ فيستجيب لكم».
[صحيح] - [رواه مسلم]

Jābir ibn ‘Abdullāh (may Allah be pleased with him) reported that the Prophet (may Allah's peace and blessings be upon him) said: "c2">“Do not supplicate against yourselves, do not supplicate against your children, and do not supplicate against your property, lest you do it at a time in which Allah answers all supplications so you will be granted what you asked for.”
Sahih/Authentic. - [Muslim]

Explanation

In this Hadīth, the Messenger of Allah (may Allah’s peace and blessings be upon him) warns of supplicating against one’s children and property, because supplication is a serious matter, and Allah may answer it if it is made in an hour when all prayers are answered. Hence, it would actually harm the person who made the supplication and his children and property.