Fiqh-us-Sunnah Volume 3, Zakaat and Fasting, Fiqh 3.103.

The jurists say that giving all of one’s property in sadaqah is permissible provided the donor is fit, earning, and steadfast, not in debt, nor has dependents for whom adequate support from him is obligatory. If he does not fulfil these conditions, then his action is makruh.

Jabir narrated: “While we were with the Messenger of Allah, upon whom be peace, a man came with what was like an egg of gold. He said: ‘O Messenger of Allah! I obtained this from buried treasure, so take it. It is sadaqah, and I do not possess anything other than it.’ The Messenger of Allah, upon whom be peace, turned away from him and he [the man] then approached him from the direction of his left side. The Messenger of Allah, upon whom be peace, then turned away from him again and he approached him from behind. Then the Messenger of Allah, upon whom be peace, took it and threw it at him. If it had hit him, it would have injured him. Then he said: ‘One of you comes with all his property to make sadaqah, then after [giving all he had] he sits [by the road] begging from the people. Sadaqah is given by the one who is rich.'” This is related by Abu Dawud and Hakim. The latter said: “It is authentic according to the stipulation of Muslim. In its transcription is Muhammad ibn Ishaq.”